The answers are:
1. A) 3
2. A) 24.5
3. C) 180
In order to find this, we need to multiply the first two together. 
1. 
15% * 20
.15 * 20
2. 
35% * 70
.35 * 70
The last problem is a little different. Since the decimal comes second, you need to divide instead of multiply. 
90/50%
90/.50