Chapter-5 Prime Time — Online MCQ Test
MATHS · Grade 6 · CBSE(NCERT)
Practice Chapter-5 Prime Time with a free chapter-wise online MCQ test.
This chapter covers: factors - multiples - prime numbers - composite numbers - HCF - LCM - divisibility rules - twin primes.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-5 Prime Time — Important Questions & Answers
What is a factor of 24?
- A. 6
- B. 7
- C. 5
- D. 9
Answer: A. 6
6 divides 24 evenly (24 ÷ 6 = 4), making it a factor of 24.
6 divides 24 evenly (24 ÷ 6 = 4), making it a factor of 24.
Which of the following is a multiple of 5?
- A. 23
- B. 35
- C. 17
- D. 41
Answer: B. 35
35 = 5 × 7, so 35 is a multiple of 5.
35 = 5 × 7, so 35 is a multiple of 5.
Which number is a prime number?
- A. 1
- B. 4
- C. 7
- D. 9
Answer: C. 7
7 has exactly two factors (1 and 7), making it a prime number.
7 has exactly two factors (1 and 7), making it a prime number.
What is a composite number?
- A. A number with only one factor
- B. A number with exactly two factors
- C. A number with more than two factors
- D. A number that cannot be divided
Answer: C. A number with more than two factors
A composite number has more than two factors (includes factors other than 1 and itself).
A composite number has more than two factors (includes factors other than 1 and itself).
If a number is divisible by 10, it must also be divisible by ___.
- A. 3 and 7
- B. 2 and 5
- C. 4 and 6
- D. 8 and 9
Answer: B. 2 and 5
Numbers divisible by 10 end in 0, making them divisible by both 2 and 5 (factors of 10).
Numbers divisible by 10 end in 0, making them divisible by both 2 and 5 (factors of 10).
Which number is NOT a factor of 36?
- A. 6
- B. 9
- C. 8
- D. 4
Answer: C. 8
36 ÷ 8 = 4.5 (not a whole number), so 8 is not a factor of 36.
36 ÷ 8 = 4.5 (not a whole number), so 8 is not a factor of 36.
If LCM(a, b) = 24 and HCF(a, b) = 4, and one number is 8, what is the other number?
- A. 6
- B. 10
- C. 12
- D. 16
Answer: C. 12
Using the formula: a × b = HCF × LCM, we get 8 × b = 4 × 24, so b = 12.
Using the formula: a × b = HCF × LCM, we get 8 × b = 4 × 24, so b = 12.
A teacher wants to distribute 48 chocolates and 36 candies equally among students with no remainder. The maximum number of students is ___.
- A. 6
- B. 8
- C. 12
- D. 18
Answer: C. 12
The maximum number of students equals HCF(48, 36) = 12. Each would get 4 chocolates and 3 candies.
The maximum number of students equals HCF(48, 36) = 12. Each would get 4 chocolates and 3 candies.
Among 91, 93, 95, and 97, which is a prime number?
- A. 91
- B. 93
- C. 95
- D. 97
Answer: D. 97
91 = 7 × 13, 93 = 3 × 31, 95 = 5 × 19, but 97 has no factors other than 1 and 97.
91 = 7 × 13, 93 = 3 × 31, 95 = 5 × 19, but 97 has no factors other than 1 and 97.
If p and q are twin primes and their product is 143, then p + q = ___.
- A. 24
- B. 26
- C. 28
- D. 30
Answer: A. 24
11 × 13 = 143 and 13 - 11 = 2 (twin primes). So p + q = 11 + 13 = 24.
11 × 13 = 143 and 13 - 11 = 2 (twin primes). So p + q = 11 + 13 = 24.