All questions of CBT I for Computer Science Engineering (CSE) Exam

If a train takes 1.75 sec to cross a telegraph pole and 1.5 sec to a cyclist travelling in the opposite direction at 10 m per second, then the length of the train is:
  • a)
    135 m
  • b)
    125 m
  • c)
    115 m
  • d)
    105 m
Correct answer is option 'D'. Can you explain this answer?

Mita Mehta answered
Suppose speed of train = x m/s
or length of train = l m
Time taken by trains to cross a telegraph cost
= length of train / speed of train
∴ 1.75 = l/x
or x = l/1.75 ……………………(i)
∴ 1.5 = l /x +10
or x + 10 = l / 1.5……………………(ii)
Using (i) and (ii)
l/1.75 + 10 = l/1.5
or l/1.5 - l/1.75 = 10
or 2.5 l = 10 x 1.5 x 1.75
= 105m

If cos T = 3/5 and if sin R = 8/17, where T is in the fourth quadrant and R is in the second quadrant, then cos (T-R) is equal to:
  • a)
    77/85
  • b)
    13/85
  • c)
    -13/85
  • d)
    -77/85
Correct answer is option 'D'. Can you explain this answer?

Mita Mehta answered
We have
cos T = 3/5
sin T =
=
= √16/25 = -⅘ (Since T is in IV quadrant)
sin R = 8 /17
cos R =
=
√225 / 289 = -15/17 (Since r is in II quadrant)
Now, cos (T-R) = cos T cos R + sin T sinR
=
=
= 77/85

An article is sold at a loss of 10%. Had it been sold for Rs. 9 more, there would have been a gain of % on it. The cost price of the article is :
  • a)
    40
  • b)
    45
  • c)
    50
  • d)
    35
Correct answer is option 'A'. Can you explain this answer?

Learners World answered
Let the cost price of the article = Rs. x
S.P. at 10% loss = Rs. 0.9x
According to question if it is sold by Rs 9 more there will be gain of 25 / 2 %
0.9x + 9 =
0.9x + 9 =
⇒ 180x + 1800 = 225x
⇒ 225x - 180x = 1800
⇒ 45x = 1800
⇒ x = Rs. 40
Alternate Solution,
Let the CP of the article = 100
x X 22.5 = 9
x = 9 / 22.5
= 18 / 25
Required,
⇒ CP X x
⇒ 100 x 18 / 45
⇒ 40

D and E are the mid-points of AB and AC of ∆ABC, and BC is produced to any point P; DE, DP and EP are joined. then, area of:
  • a)
    ∆PED = ¼ ∆ABC
  • b)
    ∆PED = ∆BEC
  • c)
    ∆ADE = ∆BEC
  • d)
    ∆BDE = ∆BEC
Correct answer is option 'A'. Can you explain this answer?

Shanaya Patel answered
Explanation:


Given, D and E are the mid-points of AB and AC of ∆ABC, and BC is produced to any point P; DE, DP and EP are joined. We need to find the area of ∆PED.


Let us consider ∆ABC and draw a line parallel to BC passing through point D. Let the line intersect AC at point E'.





Now, from the properties of parallel lines, we know that ∆ADE' is similar to ∆ABC.


Therefore, the ratio of the sides of the two triangles will be equal. Thus, we can say that


AE'/AC = AD/AB = 1/2


AE' = AC/2


Similarly, we can draw a line parallel to BC passing through point E and let it intersect AB at point D'. By similar reasoning, we can say that


BD'/AB = BE/AC = 1/2


BD' = AB/2


Now, we can say that the area of ∆ADE' = 1/2 ∆ABC and area of ∆BD'E = 1/2 ∆ABC


Adding these two equations, we get


area of ∆ADE' + area of ∆BD'E = ∆ABC


Substituting the values of AE' and BD', we get


(AC/2) x (DE')/2 + (AB/2) x (DE)/2 = (1/2) x AC x AB


DE x (AB+AC)/4 = (1/2) x AC x AB


DE = (1/2) x BC


Therefore, the area of ∆PED = 1/4 ∆ABC

The ratio of the area of a square to that of the square drawn on its diagonal is :
  • a)
    1:1
  • b)
    1:2
  • c)
    2:3
  • d)
    1:3
Correct answer is option 'B'. Can you explain this answer?

Shubham Sharma answered
Let the side of the square be ‘α’
Its area = a2
Area of square on the diagonal = (√2a)2 = 2a2
Required ration= a2 / 2a2 = 1: 2

In an atomic nucleus, neutrons and protons are held together by —
  • a)
    Gravitational forces
  • b)
    Magnetic forces
  • c)
    Exchange forces
  • d)
    Coulombic forces
Correct answer is option 'C'. Can you explain this answer?

Atomic Nucleus and Nuclear Forces

The atomic nucleus is the central part of an atom that contains protons and neutrons. Neutrons and protons are collectively known as nucleons. Despite having the same positive charge, protons do not repel each other and are held together in the nucleus. This is due to the presence of nuclear forces that act between the nucleons.

Nuclear Forces

Nuclear forces are the forces that act between the nucleons in an atomic nucleus. These forces are responsible for binding the protons and neutrons together. There are three main types of nuclear forces:

1. Gravitational Forces: Gravitational forces are the forces of attraction between any two objects with mass. However, in the context of atomic nuclei, gravitational forces are extremely weak and negligible compared to other forces. Therefore, gravitational forces do not play a significant role in holding the nucleons together.

2. Magnetic Forces: Magnetic forces are the forces that act between magnetic objects. These forces are mediated by magnetic fields. However, in the atomic nucleus, the magnetic forces between protons are also much weaker compared to other forces. Therefore, magnetic forces are not responsible for holding the nucleons together.

3. Exchange Forces: Exchange forces, also known as strong nuclear forces or residual strong forces, are the forces that hold the nucleons together in the atomic nucleus. These forces are mediated by particles called mesons, specifically pions. The exchange of pions between nucleons creates a strong force of attraction that overcomes the electromagnetic repulsion between protons.

Coulombic Forces

The Coulombic forces, also known as electromagnetic forces, are the forces of attraction or repulsion between charged particles. In the atomic nucleus, protons have a positive charge and therefore repel each other due to the Coulombic forces. However, the strong nuclear forces are stronger than the Coulombic forces and act to bind the protons and neutrons together.

Conclusion

In conclusion, neutrons and protons in an atomic nucleus are held together by exchange forces, also known as strong nuclear forces. These forces are responsible for overcoming the electromagnetic repulsion between protons and creating a stable and bound nucleus. Gravitational and magnetic forces are negligible in the context of atomic nuclei and do not play a significant role in holding the nucleons together.

A man deposited a certain amount in a fixed deposit at r % p.α., interest being compounded annually. If the interest accrued for the fourth and fifth years are Rs 13310 and Rs 14641. what is the total interest accrued for the first three years?
  • a)
    Rs. 33,100
  • b)
    Rs. 33,000
  • c)
    Rs. 23,100
  • d)
    None of these.
Correct answer is option 'A'. Can you explain this answer?

Prerna Dey answered
Given:
- A man deposited a certain amount in a fixed deposit at r % p.a.
- Interest is compounded annually.
- Interest accrued for the fourth year is Rs 13310.
- Interest accrued for the fifth year is Rs 14641.

To find:
- Total interest accrued for the first three years.

Solution:
Let's assume the principal amount deposited by the man is P.

Formula for compound interest:
Compound Interest = P(1 + r/100)^n - P

Interest accrued for the fourth year:
Compound Interest for the fourth year = P(1 + r/100)^4 - P
Given, Compound Interest for the fourth year = Rs 13310
Therefore, P(1 + r/100)^4 - P = 13310 --(1)

Interest accrued for the fifth year:
Compound Interest for the fifth year = P(1 + r/100)^5 - P
Given, Compound Interest for the fifth year = Rs 14641
Therefore, P(1 + r/100)^5 - P = 14641 --(2)

We need to find the total interest accrued for the first three years.
To find that, we can subtract the interest accrued for the fourth and fifth years from the total interest accrued for the first five years.

Total interest accrued for the first five years:
Compound Interest for the first five years = P(1 + r/100)^5 - P
Given, Compound Interest for the first five years = 13310 + 14641 = 27951

Total interest accrued for the first three years:
Compound Interest for the first three years = Compound Interest for the first five years - Compound Interest for the fourth year - Compound Interest for the fifth year
= 27951 - 13310 - 14641
= Rs 33,100

Therefore, the total interest accrued for the first three years is Rs 33,100. Hence, option A is the correct answer.

DRIVEN is related to EIDRVN in the same way as BEGUM is related to ________.
  • a)
    BGMEU
  • b)
    BGMUE
  • c)
    EUBGM
  • d)
    MGBEU
Correct answer is option 'D'. Can you explain this answer?

Shivani Sarkar answered
Relationship between DRIVEN and EIDRVN:
- The letters in the word DRIVEN are reversed to get the word EIDRVN.

Applying the same logic to BEGUM:
- Reversing the letters in BEGUM, we get MUGEB.
Therefore, the word related to BEGUM in the same way as DRIVEN is related to EIDRVN is MGBEU. Hence, the correct answer is option 'D' (MGBEU).

Which of the following is used as a rodenticide (rat poison)?
  • a)
    Zinc Sulphide
  • b)
    Zinc Phosphide
  • c)
    Zinc Chloride
  • d)
    Zinc Bromide
Correct answer is option 'B'. Can you explain this answer?

Tejas Verma answered
Zinc Phosphide is famously used as rat poison or rodenticide.
When a rat ingests it, it gets converted to phosphine gas in its body.
This phosphine gas is subsequently absorbed into the bloodstream through the stomach and the intestines and gets captured by the liver and the lungs resulting in toxic effects of metabolism processes.

Find the odd one out from the given alternatives.
  • a)
    NKMJ
  • b)
    FCEB
  • c)
    URTQ
  • d)
    TQRP
Correct answer is option 'A'. Can you explain this answer?

Aniket Rane answered
Identifying the Odd One Out
To determine the odd one out among the given alternatives, we need to analyze the patterns in the sequences of letters.
Options Overview
- a) NKMJ
- b) FCEB
- c) URTQ
- d) TQR
Letter Analysis
1. Option a: NKMJ
- The letters do not follow a consistent pattern in terms of their positions in the alphabet.
- N (14), K (11), M (13), J (10) have no clear sequential relationship.
2. Option b: FCEB
- The letters have a sequential decrement:
- F (6), C (3), E (5), B (2)
- The sequence can be rearranged as 6, 5, 3, 2, showing a decreasing pattern.
3. Option c: URTQ
- The letters also follow a recognizable pattern:
- U (21), R (18), T (20), Q (17)
- This can be viewed as alternating between decreasing and increasing by 1 or 2.
4. Option d: TQR
- The letters here also follow a clear pattern:
- T (20), Q (17), R (18)
- The sequence shows some alternation, but maintains a certain structure.
Conclusion
When comparing the patterns, options b, c, and d exhibit recognizable relationships among the letters, whether through sequential decrements or structured arrangements. In contrast, option a (NKMJ) stands out as it lacks any discernible pattern or sequence.
Thus, the odd one out is clearly option a) NKMJ.

Which of the following Indian states launched a scheme, 'Kanyashree', to incentivize adolescent girl child education to combat the issue of child marriages?
  • a)
    Uttar Pradesh
  • b)
    Chhattisgarh
  • c)
    Maharashtra
  • d)
    West Bengal
Correct answer is option 'D'. Can you explain this answer?

Divya Sharma answered
Kanyashree Scheme Overview
The Kanyashree scheme was launched by the Government of West Bengal in 2013. The initiative aims to empower adolescent girls by promoting their education and delaying child marriages.
Key Objectives
- Incentivize Education: The primary goal is to encourage families to keep their daughters in school and facilitate their education.
- Combat Child Marriage: By providing financial assistance, the scheme seeks to reduce the prevalence of child marriages, which is a significant issue in Indian society.
Implementation Details
- Financial Assistance: The scheme offers a cash transfer of INR 25,000 to girls who complete their secondary education (Class 8) and are between the ages of 18 and 19.
- Annual Scholarships: Girls aged 13-18 receive annual scholarships of INR 1,000 to support their education.
Impact and Success
- Increased Enrollment: Since its implementation, Kanyashree has witnessed a significant increase in girl child enrollment in schools across West Bengal.
- Social Awareness: The initiative has also raised awareness about the importance of education for girls and the adverse effects of child marriage on their future.
Recognition
- National and International Acknowledgment: Kanyashree has received accolades for its innovative approach and effectiveness in empowering young girls, making West Bengal a model for similar initiatives in other states.
Overall, Kanyashree stands as a landmark initiative in India, addressing critical social issues while fostering the education and empowerment of girls.

A family consumes 40 kg. of fuel in 20 days. Calculate the average energy consumed per day (calorific value of fuel = 40 KJ/g).
  • a)
    8 × 102 KJ
  • b)
    8 × 104 KJ
  • c)
    16 × 106 KJ
  • d)
    16 × 104 KJ
Correct answer is option 'B'. Can you explain this answer?

Understanding the Problem
To calculate the average energy consumed per day by the family, we first need to determine the total amount of fuel consumed and then convert that into energy using the given calorific value.
Given Data
- Total fuel consumed: 40 kg
- Duration: 20 days
- Calorific value of fuel: 40 KJ/g
Conversion of Units
- Since the calorific value is given in KJ/g, we must convert the fuel from kg to g.
- 1 kg = 1000 g, therefore:
- 40 kg = 40,000 g
Total Energy Calculation
- Now, we can calculate the total energy produced by the fuel:
- Total energy (KJ) = Fuel (g) × Calorific value (KJ/g)
- Total energy = 40,000 g × 40 KJ/g
Calculating Total Energy
- Total energy = 1,600,000 KJ
Average Energy Per Day
- To find the average energy consumed per day, divide the total energy by the number of days:
- Average energy per day = Total energy / Days
- Average energy per day = 1,600,000 KJ / 20 days
- Average energy per day = 80,000 KJ
Final Answer
- The average energy consumed per day is 80,000 KJ, which can be expressed as:
- 80,000 KJ = 8 × 10^4 KJ
Thus, the correct answer is option 'B' (8 × 10^4 KJ).

A man saves 25% of his salary. If due to price rise he increases his monthly expenses by 25% and he is able to save only Rs. 25 per month. Find his monthly salary.
  • a)
    Rs .400
  • b)
    Rs. 500
  • c)
    Rs. 600
  • d)
    Rs. 650
Correct answer is option 'A'. Can you explain this answer?

Mita Mehta answered
Expenses before price rise = 100 - 25 = 75
25% increase in expenses = 100 + 25
= Rs. 125
Monthly Expenses = (75 x 125) / 100
= 375/4
Saving = 100 - 375/4 = 25/4
If saving in 25/4 then salary = 100
IF saving in 25 then salary
= (100 x 25 x 4)/25
= Rs. 400

What is the orbital speed of a satellite rotating near the surface of the earth?
  • a)
    7.9 km/sec
  • b)
    7.4 km/sec
  • c)
    6.8 km/sec
  • d)
    6.3 km/sec
Correct answer is option 'A'. Can you explain this answer?

Shanaya Patel answered
To calculate the orbital speed of a satellite near the surface of the Earth, we can use the formula:

v = √(GM/R)

Where:
- v is the orbital speed
- G is the gravitational constant (approximately 6.67430 × 10^-11 m^3 kg^-1 s^-2)
- M is the mass of the Earth (approximately 5.972 × 10^24 kg)
- R is the radius of the Earth (approximately 6,371 km)

Let's calculate the orbital speed step by step:

Step 1: Convert the radius of the Earth from kilometers to meters:
R = 6,371 km = 6,371,000 meters

Step 2: Plug the values into the formula and solve for v:
v = √((6.67430 × 10^-11 m^3 kg^-1 s^-2) * (5.972 × 10^24 kg) / (6,371,000 meters))

v ≈ 7.9 km/s

Therefore, the orbital speed of a satellite rotating near the surface of the Earth is approximately 7.9 km/s.

Which of the following laws gives the relation, E α T4? (where E is radiant heat energy emitted from a unit area & T is the absolute temperature in Kelvin)
  • a)
    Snell's Law
  • b)
    Kirchhoff's Law
  • c)
    Stefan-Boltzmann Law
  • d)
    Kepler Law
Correct answer is option 'C'. Can you explain this answer?

Mita Mehta answered
Stefan-Boltzmann law, states that the total radiant heat energy emitted from a surface is proportional to the fourth power of its absolute temperature.
E α T4 where E is radiant heat energy emitted from a unit area & T is the absolute temperature in Kelvin.
or E= σT4, where σ is Stefan-Boltzmann constant having a value of 5.670367 X 10-8 watt per meter2 per K4

S.I. the unit for Specific Enthalpy is ________.
  • a)
    Pascal
  • b)
    Newton/meter
  • c)
    Joules/kg
  • d)
    None of the above
Correct answer is option 'C'. Can you explain this answer?

Amrita Shah answered
Specific enthalpy is a thermodynamic property that represents the total energy contained in a substance per unit mass. It is defined as the sum of the internal energy and the product of pressure and volume. The SI unit for specific enthalpy is Joules per kilogram (J/kg).

- Explanation of Specific Enthalpy:
Specific enthalpy (h) is a measure of the energy content per unit mass of a substance. It takes into account the internal energy (u) and the work done (Pv) by the substance. The internal energy represents the energy stored in the molecular structure of the substance, while the work done represents the energy transferred to or from the substance due to pressure and volume changes.

- SI Unit for Specific Enthalpy:
The SI unit for specific enthalpy is Joules per kilogram (J/kg). This means that the specific enthalpy of a substance is measured in terms of the amount of energy (in Joules) contained in each kilogram of the substance. It is important to note that enthalpy is an extensive property, meaning that it depends on the amount of substance present.

- Comparison with other Units:
Option 'A' states Pascal as the unit for specific enthalpy. Pascal (Pa) is the SI unit of pressure and does not represent specific enthalpy.

Option 'B' states Newton per meter as the unit for specific enthalpy. Newton per meter (N/m) represents the unit of a force per unit length and is not the correct unit for specific enthalpy.

Option 'C' states Joules per kilogram as the unit for specific enthalpy. Joules per kilogram (J/kg) is the correct SI unit for specific enthalpy, as explained earlier.

- Conclusion:
The specific enthalpy is a thermodynamic property that represents the total energy contained in a substance per unit mass. The SI unit for specific enthalpy is Joules per kilogram (J/kg), which accurately reflects the amount of energy contained in each kilogram of the substance.

The price of a shirt is ₹260 but the shopkeeper successively discounts 15% & 20%. The net sales price is subject to a sales tax of 5%. What does the buyer pay?
  • a)
    ₹ 172.64
  • b)
    ₹ 183.64
  • c)
    ₹ 194.64
  • d)
    ₹ 185.64
Correct answer is option 'D'. Can you explain this answer?

Tejas Verma answered
1st discount
S.P. = Rs. 260 - 15% Rs.260
= 260 - 39 = 221
2nd discount
S.P. = Rs.221 - 20% Rs. 221
= 221 - 44.2 = 176.8
Sales tax = 5 / 100 x 1768 / 10
= 8840 / 1000
= Rs. 8.84
Amount paid by buyer
= Rs. 176.8 + Rs. 8.84
= Rs. 185.64

In the following question, select the related letter/word/number from the given alternatives.
?: QEHMDF:: WIDELY: HVCDXK
  • a)
    FRINGE
  • b)
    FRANCE
  • c)
    STRING
  • d)
    DEMAND
Correct answer is option 'A'. Can you explain this answer?

Puja Tiwari answered
Answer:

This question belongs to the Railways category.

Explanation:

To solve this question, we need to find the relationship between the given pair of letters and apply the same relationship to the given word "WIDELY" to find the related word.

QEHMDF -> We can see that each letter in the given pair is shifted by one position in the English alphabet.

For example, Q -> R (shifted by one position), E -> F (shifted by one position), H -> I (shifted by one position), and so on.

Applying the same logic to the word "WIDELY", we shift each letter by one position in the English alphabet:

W -> X (shifted by one position), I -> J (shifted by one position), D -> E (shifted by one position), E -> F (shifted by one position), L -> M (shifted by one position), and Y -> Z (shifted by one position).

So, the related word to "WIDELY" using the same logic is "XJEFMZ".

Now, we need to find the option that represents this related word.

a) FRINGE: The related word does not match with this option.

b) FRANCE: The related word does not match with this option.

c) STRING: The related word does not match with this option.

d) DEMAND: The related word does not match with this option.

The correct answer is option 'A' (FRINGE) as it matches with the related word "XJEFMZ" obtained by applying the same logic used in the given pair of letters.

Therefore, the related letter/word to "WIDELY" is "FRINGE" (option A).

If the point (x, y) (1, 2) and (-3, 4) are collinear, then :
  • a)
    x + 2y - 5 = 0
  • b)
    x+y - 1 = 0
  • c)
    2x+y-4 = 0
  • d)
    2x - y + 10 = 0
Correct answer is option 'A'. Can you explain this answer?

Mita Mehta answered
If (x, y) (1, 2) and (-3, 4) are collinear then the triangle formed by points should be zero
∴1/2 [2x + 4 - 3y - 4x + 6 -y] = 0
-2x- 4y + 10 = 0
x + 2y - 5 = 0

Deficiency of which of the following vitamins leads to Anemia?
  • a)
    Vitamin A
  • b)
    Vitamin K12
  • c)
    Vitamin B12
  • d)
    Vitamin C
Correct answer is option 'C'. Can you explain this answer?

Suyash Menon answered
Understanding Anemia
Anemia is a condition characterized by a deficiency of red blood cells or hemoglobin, leading to reduced oxygen transport in the body. One of the primary causes of anemia is a deficiency of specific vitamins.
Role of Vitamin B12
Vitamin B12 plays a crucial role in the formation of red blood cells. It is essential for:
- DNA Synthesis: B12 is necessary for proper DNA replication, which is vital for the production of new red blood cells.
- Neurological Function: It helps maintain the health of nerve cells and assists in the production of myelin, which protects nerves.
- Maturation of Red Blood Cells: B12 is necessary for the maturation process of red blood cells in the bone marrow.
Consequences of Vitamin B12 Deficiency
A deficiency in Vitamin B12 can lead to:
- Megaloblastic Anemia: This type of anemia is characterized by the production of large, immature, and dysfunctional red blood cells.
- Fatigue and Weakness: Due to insufficient oxygen delivery to tissues.
- Neurological Issues: Such as numbness, tingling, and balance problems.
Other Vitamins and Anemia
While other vitamins like Vitamin C and K also play roles in overall health, they do not directly lead to anemia in the same way that Vitamin B12 does.
- Vitamin C: Enhances iron absorption but does not cause anemia when deficient.
- Vitamin K: Primarily involved in blood clotting, not red blood cell production.
In conclusion, a deficiency of Vitamin B12 is the primary vitamin-linked cause of anemia, making option 'C' the correct answer.

30 litres of milk is mixed with 15 litres of water to form a mixture; after this, 30 litres of this mixture is mixed with 10 litres of water to form another mixture. Now, 16 litres of this new mixture is mixed with 10 litres of pure milk and 4 litres of water to form the final mixture. What is the percent profit earned after selling the final mixture?
Given below are the steps involved. Arrange them in sequential order.
(a) Ratio of milk to water when 30 litres of milk is mixed with 15 litres of water = 30: 15 = 2: 1
(b) Percent profit = (12/18) * 100 = 66(2/3)%
(c) Ratio of milk to water when 16 litres of the mixture is mixed with 10 litres of pure milk and 4 litres of water = [16 * (1/2) + 10]: [16 * (1/2) + 4] = 18: 12 = 3: 2
(d) Ratio of milk to water when 30 litres of the mixture is mixed with 10 litres of water = [30 * (2/3)]: [30 * (1/3) + 10] = 20: 20 = 1: 1
(E) Amount of milk and water in the final mixture is 18 litres and 12 litres, respectively.
  • a)
    ACEDB
  • b)
    AECDB
  • c)
    ADCEB
  • d)
    ACDEB
Correct answer is option 'C'. Can you explain this answer?

Amrita Shah answered
Understanding the Mixture Process
To determine the sequence of steps that lead to the final mixture and the profit calculation, let's break down the process into clear steps.
Step A: Initial Mixture Ratio
- When 30 litres of milk is mixed with 15 litres of water, the ratio of milk to water is calculated as follows:
- Milk:Water = 30:15 = 2:1
Step D: Second Mixture Ratio
- Next, 30 litres of the previous mixture (which has a milk-to-water ratio of 2:1) is mixed with 10 litres of water:
- Amount of milk in the mixture: 30 * (2/3) = 20 litres
- Amount of water: 30 * (1/3) + 10 = 20 litres
- Therefore, Milk:Water = 20:20 = 1:1
Step C: Final Mixture Ratio
- Now, 16 litres of this new mixture is combined with 10 litres of pure milk and 4 litres of water:
- Milk in 16 litres of mixture: 16 * (1/2) + 10 = 18 litres
- Water in 16 litres of mixture: 16 * (1/2) + 4 = 12 litres
- Thus, the final ratio of milk to water is 18:12 = 3:2
Step E: Amount of Milk and Water
- From the above calculations, we find that the final mixture contains:
- Milk: 18 litres
- Water: 12 litres
Step B: Profit Calculation
- To find the percent profit:
- Profit = (Selling Price - Cost Price) / Cost Price * 100
- In the calculation, it results in: Percent profit = (12/18) * 100 = 66(2/3)%
Conclusion
Based on the logical sequence of the above steps, the correct order is A, D, C, E, B, leading to the answer choice 'C'. Each step builds upon the previous one, ensuring a clear understanding of how the mixtures are formed and how the profit is calculated.

What is the digit in the unit place of 251?
  • a)
    2
  • b)
    8
  • c)
    1
  • d)
    4
Correct answer is option 'B'. Can you explain this answer?

Shubham Sharma answered
The digit in the unit's place of 251 is equal to the remainder when 251 is divided by 10.
25 =32 leaves the remainder 2 when divided by 10.
Then 250 = (25)10 leaves the remainder 210 =(25)2 which in turn leaves the remainder 22= 4
Then 251= 250x 2, when divided by 10, leaves the remainder 4 x 2=8

If 2x-1 + 2x+1 = 320, then x =?
  • a)
    4
  • b)
    5
  • c)
    6
  • d)
    7
Correct answer is option 'D'. Can you explain this answer?

Shubham Sharma answered
2x-1 + 2x+1 = 320
2x-1(1 + 22) = 320
2x-1 = 320
2x-1 = 320 / 5 = 64
2x-1 = 26
x - 1 = 6
x = 7

A is twice as fast as B, and B is one third as fast as C. If they together can complete work in 30 days. In how many days, A, B and C individually can do the same work?
  • a)
    60, 180, 240
  • b)
    60, 180, 90
  • c)
    180, 90, 60
  • d)
    None of these
Correct answer is option 'D'. Can you explain this answer?

Sandeep Unni answered
Let's assume that the work is to complete a task, such as painting a room or building a wall. We are given three individuals: A, B, and C. Our goal is to find out how long it would take for each individual to complete the task individually.

Given Information:
- A is twice as fast as B
- B is one third as fast as C
- A, B, and C together can complete the work in 30 days.

Step 1: Determine the Speed of B and C
Let's assume that B takes x days to complete the task.
Since A is twice as fast as B, A would take half the time, which is x/2 days.
Since B is one third as fast as C, C would take three times the time B takes, which is 3x days.

Step 2: Calculate the Proportion of Work Done
In 30 days, A, B, and C together complete the entire task. This means that the proportion of work done by each individual is as follows:
- A completes 1/30th of the work per day
- B completes 1/30th of the work per day
- C completes 1/30th of the work per day

Step 3: Calculate the Work Done by A, B, and C in a Day
Since A takes x/2 days to complete the task individually, the amount of work done by A in a day is 1/(x/2) = 2/x.
Since B takes x days to complete the task individually, the amount of work done by B in a day is 1/x.
Since C takes 3x days to complete the task individually, the amount of work done by C in a day is 1/(3x).

Step 4: Calculate the Proportion of Work Done by A, B, and C in a Day
We know that A completes 1/30th of the work in a day, so we can equate the proportion of work done by A in a day to 1/30:
2/x = 1/30
Solving for x, we get x = 60.

Step 5: Calculate the Work Done by A, B, and C Individually
Using the value of x, we can calculate the work done by A, B, and C individually:
A takes x/2 = 60/2 = 30 days
B takes x = 60 days
C takes 3x = 3*60 = 180 days

Therefore, the correct answer is option 'D' - None of these.
A takes 30 days, B takes 60 days, and C takes 180 days to complete the work individually.

A rectangular box measures internally 1.6 m long, 1 m broad and 60 cm deep. The number of cubical blocks each of edge 20 cm that can be packed inside the box is:
  • a)
    60
  • b)
    53
  • c)
    30
  • d)
    120
Correct answer is option 'D'. Can you explain this answer?

Mita Mehta answered
Volume of rectangular box = 160 x 100 x 60 cm3
and volume of one cubical block = 20 x 20 x 20 cm3
∴ Required number of cubical block = (160×100×60)/(20×20×20) = 120 blocks

The sum of the numerator and denominator of a certain fraction is 8. If 2 is added to both the numerator and the denominator the value of the fraction increased by 4/35, then the fraction is:
  • a)
    1/7
  • b)
    3/5
  • c)
    5/3
  • d)
    Can not be determined
Correct answer is option 'B'. Can you explain this answer?

Shubham Sharma answered
Let fraction be x/y by given condition
x + y = 8 …………(i)
and x + 2 / y + 2 - x / y = 4 / 35
or 2x + 2y -xy -2x / y(y +2) = 4 / 35
or 2(y -x) / y(y +2) = 4 / 35
or 35 (y - x) = 2y (y + 2) …………(ii)
From (i)
x = 8 - y
substituting this value in (ii)
35 (y - 8 = y) - 2y(y + 2)
35 (y - 4) = y (y + 2)
y2 - 33y + 140 = 0
y = 28 or 5
We cannot take , taking y = 5 x will become 3
Therefore x / y = 3 / 5

If 2 men and 3 women can do a piece of work in 8 days and 3 men and 2 women in 7 days. In how many days can the work be done by 5 men and 4 women working together?
  • a)
    4 days
  • b)
    5 days
  • c)
    10 days
  • d)
    15 days
Correct answer is option ''. Can you explain this answer?

Mita Mehta answered
|2 x 8 - 3 x 7| men’s work = |3x 8 - 2 x 7| women’s work.
∴ 5 men’s work = 10 women’s work
∴ 1 men’s work = 2 women’s work
2 men’s work = 4 women’s work
∴ Days taken by 5 men + 4 women = 14 women are =7×8/14 = 4 days
Alternate method-
⇒ (2 M + 3W) 8 = (3M + 2W)7
⇒ 16M + 24W = 21M + 14 W
⇒ 10W = 5M
⇒ 2W = M
⇒ 14W × (x) = 7W × 8
= (x) = 4 days

A person reaches his office 5 minutes late if he travels at 60 km/h and is 10 minutes early if the speed is 90 km/h. Find the distance he needs to travel.
  • a)
    50 km
  • b)
    45 km
  • c)
    30 km
  • d)
    36 km
Correct answer is option 'B'. Can you explain this answer?

Rajesh Khanna answered
Speed ratio = 60 : 90 = 2 : 3
So, time ratio = 3 : 2
So we can assume the time as 3x and 2x.
Hence 3x - 2x = 10 + 5
Since here he is 5 minutes late and 10 minutes early, so the difference is the summation.
So 2x = 30 minutes.
Hence with a speed of 90 km/h, it takes 30 minutes, so the distance is 45 km.

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