Risa is 20% heavier than Peter. Tiffany is 40% lighter than Peter. Risa is 9 kg heavier than Tiffany. What is Peter's mass?
| Risa |
Peter |
Tiffany |
| 120% |
100% |
|
| |
100% |
60% |
| 6 u |
5 u |
3 u |
Risa's mass compared to Peter's mass in percent
= 100% + 20%
= 120%
Tiffany's mass compared to Peter's mass in percent
= 100% - 40%
= 60%
120% =
120100 =
6560% =
60100 =
35Peter's mass is the repeated identity. Make Peter's mass the same.
Peter's mass = 5 u
Mass that Risa has more than Tiffany
= 6 u - 3 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Peter's mass
= 5 u
= 5 x 3
= 15 kg
Answer(s): 15 kg
