Question

15 % of what number is 21 thanks :)

Answer 1

The answer is 140 that should help tou

Answer 2

15% of x = 21
Set up proportions.
15/100 = 21/x
Cross multiply the numbers (15 by x, 21 by 100).
Divide 2100 by 15x to get x.
2100/15 = 140
X is 140.