Question

Which are the numbers between 1 and 50 having exactly four factors

Answer 1

Answer:

For this, we have to first list all the prime numbers such that their squares are below 50.

First few prime numbers such that the square of the same is below 50, are:

2, 3, 5 and 7

and their squares respectively are:

4, 9, 25 and 49

Now, these are the numbers, which are having exactly 3 factors.

4: 1, 2 and 4

9: 1, 3 and 9

25: 1, 5 and 25

49: 1, 7 and 49