1. 15 is what percent of 40?
2. 15 is 30% of what number?
3. what number is 120% of 70?

1. 15 is what percent of 40?
   15 * 100 / 40 = 37.5
answer is 15 is 37.5% of 40

2. 15 is 30% of what number?
 15 / 0.3 = 50
answer : 15 is 30% of 50

3. What number is 120% of 70?
120% = 1.2
1.2 + 1 = 2.2

2.2 * 70 = 154
154 is 120% of 70?