Question

The square of a certain whole number N is N^2. If 60 is a factor of N^2, it's possible that blank is not a factor of N^2

15
25
36
100

Answer 1

`60 = 2 * 2 * 3 * 5`

If 60 is a factor of
`N^2` then 2, 3 and 5 are necessarily factors of
`N`. So 30 is a factor of N, so 900 is a factor of
`N^2`. So any factors of 900 are necessarily a factor of
`N^2`.

Let's go through the list.

15) 900/15=60, so 15 is definitely a factor of
`N^2`.

25) 25 divides 900, definitely a factor

36) 36 divides 900, definitely a factor

100) 100 divides 900, definitely a factor

Answer: none of the above are not factors