Question

Sum of the number of primes between 16 to 80 and 90 to 100 is ______.

Options

• 20

• 18

• 17

• 16

Answer 1

Sum of the number of primes between 16 to 80 and 90 to 100 is 17.

Explanation:

Prime numbers between 16 to 80 are 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73 and 79.

So, there are 16 prime numbers between 16 to 80.

Also, 97 is the only prime number between 90 to 100.

So, there is only 1 prime number between 90 to 100.

∴ Required sum = 16 + 1 = 17