Q1: Suppose you toss a coin twice what is the probability of tossing two heads?
(a) 1/16
(b) 1/4
(c) 1/8
(d) 1/5
Ans: (b)
Sol: To find the probability of tossing two heads when you toss a coin twice, you can use the concept of independent events. When you toss a fair coin, the probability of getting a head (H) or a tail (T) on each toss is 1/2.
Since the two coin tosses are independent events, you can multiply the probabilities together to find the probability of both events happening.
The probability of getting a head on the first toss is 1/2, and the probability of getting a head on the second toss is also 1/2.
So, the probability of getting two heads (HH) is:
(1/2) x (1/2) = 1/4
So, the correct answer is (b) 1/4.
Q2: One trillion is 1 followed by 12 zeros. What is 1 followed by 18 zeros?
(a) 1 quadrillion
(b) 1 quintillion
(c) 1 septillion
(d) 1 octillion
Ans: (b)
Sol: 1 trillion is 1 followed by 12 zeros, which can be written as:
1,000,000,000,000
Now, if we want to represent 1 followed by 18 zeros, we simply add six more zeros to the end:
1,000,000,000,000,000,000
This number is known as one quintillion. So, the answer is (b) 1 quintillion.
Q3: Ms. Ben wrote four numbers on the board and asked the student to relate them according to the last lesson taught on number system. Which of the following number she wrote is different from others?
(a) 10 hundred
(b) 100 hundred
(c) 1000 hundred
(d) 100000 lakh
Ans: (d)
Sol: To relate these numbers according to the number system, let's break down each of them:
(a) 10 hundred = 10 * 100 = 1,000
(b) 100 hundred = 100 * 100 = 10,000
(c) 1000 hundred = 1000 * 100 = 100,000
(d) 100000 lakh = 100,000 * 100 = 10,000,000
Now, let's compare these numbers:
(a) 1,000
(b) 10,000
(c) 100,000
(d) 10,000,000
The number (d) 10,000,000 is different from the others as it is much larger than the rest. So, the correct answer is (d) 100000 lakh.
Q4: Insert commas in the correct positions to separate periods and write the following number in words.
10105607
Sol: After inserting commas, the number will be 1,01,05,607.
1,01,05,607 = One crore one lakh five thousand six hundred seven
Q5: Write 10075302 in words and rearrange the digits to get the smallest and the largest numbers.
Sol: 1,00,75,302= One crore seventy five thousand three hundred two
Rearranging the digits,
Largest number = 7,53,21,000
Smallest number = 1,00,02,357
Q6: Insert commas in the correct positions to separate periods and write the following number in words.
9050784
Sol: After inserting commas, the number will be 90,50,784.
90,50,784 = Ninety lakhs fifty thousand seven hundred eighty four
Q7: How many grams should be added to 2 kg 300 g to make it 5 kg 68 g?
Sol:
Step 1: Convert kg to grams
We know that 1 kg = 1000 g
So, 2 kg 300 g = 2×1000 g + 300 g
= 2000 g + 300 g
Similarly 5 kg 68 g = 5 × 1000 g + 68 g
= 5000 g + 68 g
= 5068 g
Step2: Finding the difference
To find what weight is to be added we need to find the difference between the two weights.
Difference = 5068 g − 2300 g
= 2768 g
Hence, 2768 g is to be added to 2 kg 300 g to get 5 kg 68
Q8: Read the number:
9,76,987
(a) Nine lakh seventy six thousand nine hundred eighty seven.
(b) Nine lakh seventy six thousand nine hundred seventy eight.
(c) Nine lakh eighty six thousand nine hundred eighty seven.
(d) None of these
Ans: (a)
Sol: 9,76,987
This number has 9 at lakh's place, 7 at ten thousand's place, and so on, and is read as
Nine lakh seventy six thousand nine hundred eighty seven.
Q9: Insert commas in the correct positions to separate periods and write the following number in words:
10000007
Sol: After inserting commas, the number will be 1,00,00,007.
1,00,00,007 = One crore seven
Q10: How many lakhs make a billion?
Sol: 1 billion =1,000,000,000
1 lakh=1,00,000
So, 1 billion = 10,000×(1,00,000)
1 billion =10,000 lakhs
Q11: How many lakhs make a million?
Sol: 1.000.000=10×1,00,000=10 lakhs
Q12: Insert commas in the correct positions to separate periods and write the following number in words:
857367
Sol: After inserting commas, the number will be 8,57,367.
8,57,367 = Eight lakhs fifty seven thousand three hundred sixty seven
Q13: Fill in the blanks :
If a unit cm (centimeter) is taken 5 times, the corresponding quantity is _____
Sol: If a unit cm (centimeter) is taken 5 times, the corresponding quantity is 5cm.
Q14: How many thousands make a lakh?
(a) 10
(b) 100
(c) 1000
(d) 10000
Ans: (b)
Sol: 1 lakh means 1,00,000 which is equal to one hundred thousand
Therefore 1,00,000=(100×1000)
Hence one hundred thousands make a lakh.
Q15: If a boy weighs 35 kg and a girl weighs 27 kg, then who is heavier and by how much amount?
(a) 7
(b) 6
(c) 8
(d) 5
Ans: (c)
Sol: Boy weighs 35 kg and a girl weighs 27 kg
So, the boy is heavier and he is heavy by = (35 − 27)kg = 8kg
So, option C is the answer
Q16: If a new born baby is 30 cm in length and you are 4 times taller than this baby, then what is your height?
(a) 34 cm
(b) 26 cm
(c) 150 cm
(d) 120 cm
Ans: (d)
Sol: If the newborn baby is 30 cm in length, and you are 4 times taller than the baby, you can calculate your height as follows:
Your height = 4 x (baby's height)
Your height = 4 x 30 cm = 120 cm
So, the correct answer is (d) 120 cm.
Q17: If a shark of length 10 meters and a whale of length 16 meters are kept aside each other, what is difference between their lengths ?
(a) 5
(b) 6
(c) 7
(d) 8
Ans: (b)
Sol: Length of shark = 10 metres
length of whale = 16 metres
Difference between the length of shark and whale = 16 -10
= 6 metres
Q18: Fill in the blanks :
10 coins - one coin = _________
Sol: 10 coins - one coin = 9 coins
Q19: If smaller fish is 2 cm in length and larger fish is 20 cm in length, then how many times larger fish is bigger than smaller fish?
(a) 20 times
(b) 10 times
(c) 5 times
(d) 15 times
Ans: (b)
Sol: Smaller fish is 2 cm in length
Larger fish is 20 cm in length
∴ Larger fish=10×2 cm in length
= 10 times length of smaller fish
Q20: If out of 60 students in a class, 10 students got distinction, 30 students got first class, 13 students got second class and remaining students failed, then how many students failed in exam?
(a) 10
(b) 7
(c) 9
(d) 12
Ans: (b)
Sol: To find out how many students failed in the exam, you can subtract the number of students who passed from the total number of students in the class.
Total number of students = 60
Number of students who got distinction = 10
Number of students who got first class = 30
Number of students who got second class = 13
So, the total number of students who passed = 10 (distinction) + 30 (first class) + 13 (second class) = 53.
Now, to find the number of students who failed, subtract the number who passed from the total:
Total number of students - Number of students who passed = 60 - 53 = 7
So, the correct answer is (b) 7 students failed in the exam.
