Important Questions
Multiple Choice Questions:
1. What are the numbers which have more than two factors called?
(A) Even numbers
(B) Prime numbers
(C) Composite numbers
(D) Odd numbers
2. The sum of two odd and one even numbers is:
(A) Even
(B) Prime
(C) Composite
(D) Odd
3. The number which is divisible by 5 is:
(A) 422
(B) 423
(C) 424
(D) 425
4. The HCF of 12 and 40 is:
(A) 3
(B) 4
(C) 5
(D) 6
5. Every ______ of a number is greater than or equal to that number.
(A) factor
(B) number
(C) multiple
(D) none to these
6. What is the H.C.F. of two co-prime numbers?
(A) 1
(B) 0
(C) 2
(D) 4
7. The LCM of 12, 15, 45 is:
(A) 170
(B) 180
(C) 190
(D) 200
8. Find the HCF of 27, 63.
(A) 2
(B) 6
(C) 3
(D) 9
9. ______ is the smallest prime number which is even:
(A) 2
(B) 4
(C) 3
(D) 1
10. If a number is divisible by 10, then which of the following can be its one’s digit?
(A) 2
(B) 3
(C) 4
(D) 0
11. The value of 10 + 40 ÷ 8 × 2 – 9 is:
(A) 9
(B) 10
(C) 11
(D) 12
12. The number which is divisible by 3 is:
(A) 135
(B) 136
(C) 137
(D) 139
13. The only prime number which is also even is
(A) 6
(B) 1
(C) 2
(D) 4
14. Which of the following is the L.C.M. of 36 and 72?
(A) 36
(B) 72
(C) 108
(D) 2
15. A prime number is a number which:
(A) is divisible by 2
(B) is not divisible by 2
(C) has no factors
(D) has exactly two factors
Match The Following:
Fill in the blanks:
1. 1 is neither _____ nor _____.
2. The smallest prime number is _____.
3. The smallest composite number is _____.
4. The smallest even number is _____.
True /False:
1. A number with 4 or more digits is divisible by 8, if the number formed by the last three digits is divisible by 8.
2. If the sum of the digits of a number is divisible by 3, then the number itself is divisible by 9.
3. All numbers which are divisible by 4 may not be divisible by 8.
4. The Highest Common Factor of two or more numbers is greater than their Lowest Common Multiple.
Very Short Questions:
1. Find LCM of 60 and 40.
2. Write all the factors of the following number: 27
3. List all the multiples of 7 that lie between 125 and 142.
4. Find the H.C.F of the following numbers. 70, 105, 175
5. Find the H.C.F of the following numbers. 27, 63
6. Find all the multiples of 9 upto 100.
7. Find the least 4-digit number which is exactly divisible by 8, 10, and 12.
8. What is the sum of any two?
(a) even numbers
(b) odd numbers
9. Which of the following numbers is divisible by 3?
(a) 1212
(b) 625
10. If the LCM and HCF of any two numbers are 15 and 4 respectively,
find the product of the numbers.
11. Find the HCF of 5 and 7.
12. Write first 3 multiples of 25.
13. What are the possible factors of (a) 12 (b) 18?
14. Write first three multiples of 11.
15. Write pairs of twin prime numbers less than 20.
Short Questions:
1. Simplify: 32 + 96 ÷ (7 + 9)
2. Simplify: 18 + {1 + (5 – 3) x 5}
3. Without actual division, show that 11 is a factor of 1,10,011.
4. The sum of two numbers is 25 and their product is 144. Find the numbers.
5. Is 80136 divisible by 11?
6. The HCF and LCM of two numbers are 6 and 120 respectively. If one of the numbers
is 24, find the other number.
7. Find the LCM of 12 and 30.
8. Find the smallest 4-digit number which is divisible by 18, 24 and 32.
9. Find the greatest number which divides 82 and 132 leaving 1 and 6, respectively as remainders.
10. Find the greatest number that will divide 455, 582 and 710 leaving remainders 14, 15 and 17 respectively.
Long Questions:
1. Three sets of English, Hindi, and Urdu books are to be stacked in such a way that the books are stored
subject wise and the height of each stack is the same. The numbers of English, Hindi and Urdu books
are 336, 192 and 144 respectively. Assuring that the books have that same thickness, determine the
number of stacks of English, Hindi and Urdu books.
2. Ill cows, 185 sheep and 296 goats are to be taken across a river. There is only one boat and the boatsman
says; he will take the same number and same kind of animals in each trip. Find the largest number of
animals in each trip and the number of trips he will have to make.
3. In a seminar, the number of participants in Mathematics, Physics and Chemistry are 60, 96 and 144 respectively.
Find the number of rooms required if in each room, the same number of ‘ participants are to be seated and all
of them are to be in the same subject.
Assertion and Reason Questions:
(1.) Assertion (A) – The factors of 34 are 1, 2, 17 and 34 itself
Reason (R) – every factor is less than or equal to the given number.
(a) Both A and R are true and R is the correct explanation of A
b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
(2.) Assertion (A) –The factors of 8 are 1, 2, 4, 8.
Reason (R) – every factor of a number is an exact divisor of that number.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true