Which of the following is a prime number?

Which of the following is a prime number?
(a) 69
(b) 87
(c) 91
(d) 97

Solution:

Which of the following is a pair of twin- prime number?
(a) 19, 21
(b) 43, 47
(c) 59, 61
(d) 73, 79

Solution:

The number of distinct prime factors of the largest 4-digit number is
(a) 2
(b) 3
(c) 5
(d) none of these

Solution:

More Solutions:

• All factors of 6 are
• The number of distinct prime factors.
• Every natural number has an infinite number of
• Which of the following numbers is divisible by 3?
• The digit by which ‘*’ should be replaced in 54 * 281.
• The number of common prime factors of 60, 75 and 105 is