Wendy had
35 as much money as Lucy. Wendy had $36 less than Lucy. Wendy spent some money to buy a birthday present for her mother. In the end, she had
12 as much money as Lucy. How much did Wendy spend on the birthday present?
|
Wendy |
Lucy |
Before |
3 u |
5 u |
Change |
- ? |
|
After |
1 p |
2 p |
Amount that Wendy had less than Lucy
= 5 u - 3 u
= 2 u
2 u = 36
1 u = 36 ÷ 2 = 18
Amount that Wendy had at first
= 3 u
= 3 x 18
= $54
Amount that Lucy had
= 5 u
= 5 x 18
= $90
The amount that Lucy had at first and in the end remains the same.
5 u = 2 p
2 p = 90
1 p = 90 ÷ 2 = 45
Amount that Wendy had in the end
= 1 p
= $45
Amount that Wendy spent on the birthday present
= 54 - 45
= $9
Answer(s): $9