How many prime numbers lie between 1 and 40?
The prime numbers between 1 and 40 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31 and 37. Hence, there are 12 prime numbers that lie between 1 and 40.
How many prime numbers are there between 1 and 10000?
How many prime numbers are there between 1 and 20?