Convert 21/105 into it's simplest form.

The answer is 1/5. As 21 is a factor of 105 (21 x 5 = 105), we are able to divide 21 by itself to get 1, and divide 105 by 21 to get 5. Therefore 1/5.

1 x 21 = 21

5 x 21 = 105

so answer is 1/5

=1/5. The numerator and denominator are both divisible by 7, which then leaves you with 3/15. 3 and 15 are both divisible by 3, thus leaving you with 1/5.