Test: Mental Ability (Arithmetic Reasoning) - Software Development MCQ

Given:

No of possible outcomes when two dice are thrown simultaneously: 6 × 6 = 36 

(1,1), (1, 2), (1, 3),  (1, 4), (1, 5), (1, 6) 

(2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6) 

(3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6) 

(4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6)

(5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5, 6)

(6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)

Formula used:

Probability = No of favorable outcome ÷ No of total outcomes 

Calculation:

No of outcome with sum 12 (6, 6) = 1

∴ Required probability = 1/36 

Given:

Man rows 24 km in upstream and 40 km in downstream and takes 8 hours in each

Formula used:

Speed = Distance/Time

y = ½ (u - v); where, u is speed of rowing downstream, v is speed of rowing upstream and y is speed of stream

Calculation:

Downstream speed = u = 40/8 = 5 kmph

Upstream speed = v = 24/8 = 3 kmph

Given:

The ratio of the present age of Annu and Raj = 4 : 5

Then after 8 years ratio of their age = 5 : 6

Calculation:

Let be assume the present age of Annu and Raj is 4x and 5x respectively

⇒ (4x + 8)/(5x + 8) = 5/6

⇒ 24x + 48 = 25x + 40

⇒ x = 8

⇒ The age of Annu = 4x = 4 × 8 = 32

⇒ The age of Raj = 5x = 5 × 8 = 40

∴ The required result will be 32 years, and 40 years respectively.

Let CP of the article be Rs. 100

⇒ SP of the article = 100 × 180/100 = Rs. 180

New cost price = 100 × 120/100 = Rs. 120

⇒ New profit = 180 – 120 = 60

Profit percentage = 60/120 × 100 = 50%

Given:

Mohit got 30% marks and failed by 25 marks

Another student scored 38% and

He got 15 more marks than passing marks

Calculation:

According to the question

⇒ 30% + 25 = 38% – 15

⇒ (38% – 30%) = (15 + 25)

⇒ 8% = 40

⇒ 1% = 5 marks

Now,

5% = 25 marks 

Then,

The necessary pass percentage required = (30% + 5%)

⇒ 35%

∴ Required pass percentage is 35%

Given

Ratio of principal and amount is 4 : 5 at a certain time. If it becomes 5 : 7 after 3 years

Concept used

Rate = (interest × 100)/(Principal × time)

Calculation

Principal : Amount = 4 : 5

Principal be equal 

Multiply the first ratio with 25 and second with 20

⇒ (4 : 5) × 25 

⇒ (5 : 7) × 20

Principal : Amount = 100 : 125

Principal : Amount = 100 : 140

Difference in amount = 140 - 125

Difference in Amount = 15

3 year = 15

1 year = 5

Rate = (interest × 100) / Principal × time

Rate = 

Rate = 5%

∴ The required simple rate of interest is 5%.

Given:

Speed of train₁ = 32 km/h

Speed of train₂ = 40 km/h

Length of train₁ = 132 m

Length of train₂ = 108 m

Formula used:

If bodies moving in opposite direction = (x + y) km/h

If bodies moving in same direction = (x – y) km/h

Speed = Distance/Time

1 km/h = (5/18) m/sec

Calculation:

The sum of the length of the train = (132 + 108) m

⇒ 240m

According to the question

Relative speed = (32 + 40) km/h

⇒ 72 km/h

⇒ (72 × 5/18) m/sec = 20 m/sec

Now,

Time taken = Total distance/Speed

⇒ (240/20) sec

⇒ 12 sec

∴ Required time is 12 sec

Given:

Efficiency of Amit = 2 × Efficiency of Ramit

Concept used:

Total work = Efficiency × Time period

Calculation:

The efficiency of Amit = 2

Efficiency of Ramit = 1

Total work = (2 + 1) × 28 = 3 × 28 = 84

Number of days Ramit takes to complete the whole work = 84/1 = 84

∴ The number of days in Ramit will complete the work is 84 days.

GIVEN:

The average of 40 numbers = 25

CONCEPT:

Basic Average concept.

FORMULA USED:

Average = Sum of all numbers/Total numbers

CALCULATION:

Sum of numbers = 40 × 25 = 1000

23, 25 and 41 are mistakenly written as 32, 52 and 15 respectively.

⇒ Change in sum = (23 + 25 + 41) – (32 + 52 + 15)

= 89 – 99

= -10

Actual sum of numbers will be 10 less.

⇒ Sum of numbers = 1000 – 10 = 990

∴ Correct average = 990/40 = 24.75

Given:

Length of rectangle = 3/5 of radius of circle

Radius of circle = Side of square with area 6400 m2

Breadth of rectangle = 15 m 

Formulas used:

Area of square = (Side)²

Perimeter of rectangle = 2(Length + Breadth) 

Calculation:

Area of square = 6400 m2

⇒ Side² = 6400 

⇒ Side = √6400 = 80 m 

Radius of cirlce = Side of square = 80 m 

⇒ Length of rectangle = 3/5 × 80 = 48 m 

∴ Perimeter of the rectangle = 2(48 + 15) m 

⇒ 126 m