Question

From 1 to 100 ,how many numbers have exactly three factors. Full explanations ​

Answer 1

Answer:

This may help u.

Step-by-step explanation:

All the prime numbers, for example 2,3,5,7... have only 2 factors, that is, 1 and the number itself.

All composite numbers, for example 4,6,8,9...have more than 3 factors.

So, only the squares of the prime numbers are the only numbers which have exactly three factors.

Such numbers between 1 and 100 are 4,9,25 and 49.