Zoe is 20% heavier than Sam. Roshel is 10% lighter than Sam. Zoe is 9 kg heavier than Roshel. What is Sam's mass?
| Zoe |
Sam |
Roshel |
| 120% |
100% |
|
| |
100% |
90% |
| 12 u |
10 u |
9 u |
Zoe's mass compared to Sam's mass in percent
= 100% + 20%
= 120%
Roshel's mass compared to Sam's mass in percent
= 100% - 10%
= 90%
120% =
120100 =
121090% =
90100 =
910Sam's mass is the repeated identity. Make Sam's mass the same.
Sam's mass = 10 u
Mass that Zoe has more than Roshel
= 12 u - 9 u
= 3 u
3 u = 9
1 u = 9 ÷ 3 = 3
Sam's mass
= 10 u
= 10 x 3
= 30 kg
Answer(s): 30 kg
