Solved Questions on Prime Numbers
1. Which of the following is a prime number?
a) 10
b) 17
c) 24
d) 33
Answer: b) 17
Explanation: 17 is a prime number. It has exactly two divisors, 1 and 17, and is not divisible by any other positive integer.
2. Which of the following is not a prime number?
a) 2
b) 3
c) 5
d) 6
Answer: d) 6
Explanation: 6 is not a prime number. It has more than two divisors, namely 1, 2, 3, and 6.
3. Which of the following is a composite number?
a) 11
b) 13
c) 15
d) 19
Answer: c) 15
Explanation: 15 is a composite number. It is divisible by 1, 3, 5, and 15.
4. What is the smallest prime number greater than 10?
a) 11
b) 13
c) 15
d) 17
Answer: a) 11
Explanation: The smallest prime number greater than 10 is 11, which has exactly two positive divisors (namely, 1 and 11).
5. What is the largest prime number less than 20?
a) 17
b) 19
c) 21
d) 23
Answer: b) 19
Explanation: The largest prime number less than 20 is 19, which has exactly two positive divisors (namely, 1 and 19).
Practice Questions on Prime Numbers
1. Which of the following is not a prime number?
a) 23
b) 27
c) 29
d) 31
Answer: b) 27
2. What is the sum of the first 10 prime numbers?
a) 68
b) 129
c) 184
d) 223
Answer: b) 129
3. What is the only even prime number?
a) 1
b) 2
c) 3
d) 4
Answer: b) 2
4. How many prime numbers are there between 50 and 70?
a) 3
b) 4
c) 5
d) 6
Answer: b) 4 (53, 59, 61, 67)
5. What is the sum of the prime numbers less than 10?
a) 17
b) 26
c) 37
d) 50
Answer: a) 17
6. Which of the following numbers is not prime?
a) 192 - 2
b) 272 - 2
c) 312 - 2
d) 372 - 2
Answer: c) 312 - 2
7. What is the odd prime number?
a) 13
b) 14
c) 15
d) 16
Answer: a) 13
8. What is the next prime number after 89?
a) 91
b) 93
c) 97
d) 99
Answer: c) 97
9. Which of the following is a composite number?
a) 31
b) 37
c) 41
d) 49
Answer: d) 49
10. What is the next prime number after 11?
a) 10
b) 12
c) 13
d) 14
Answer: c) 13
