Olivia is 30% heavier than David. Joelle is 20% lighter than David. Olivia is 20 kg heavier than Joelle. What is David's mass?
| Olivia |
David |
Joelle |
| 130% |
100% |
|
| |
100% |
80% |
| 13 u |
10 u |
8 u |
Olivia's mass compared to David's mass in percent
= 100% + 30%
= 130%
Joelle's mass compared to David's mass in percent
= 100% - 20%
= 80%
130% =
130100 =
131080% =
80100 =
810David's mass is the repeated identity. Make David's mass the same.
David's mass = 10 u
Mass that Olivia has more than Joelle
= 13 u - 8 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
David's mass
= 10 u
= 10 x 4
= 40 kg
Answer(s): 40 kg
