Question

how many prime no are there in between 16 to 80

Answer 1

 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79,  prime number less  then 80.  are 21.....

Answer 2

The prime numbers between 16 to 80 are--
17, 19, 23, 29, 31, 41, 37, 43, 47, 49, 53, 57, 59, 61, 67, 71, 73, 79
Therefore, there are 18 prime numbers between 16 and 80.