Cathy had
310 as much money as Eva. Cathy had $49 less than Eva. Cathy spent some money to buy a birthday present for her uncle. In the end, she had
17 as much money as Eva. How much did Cathy spend on the birthday present?
| |
Cathy |
Eva |
| Before |
3 u |
10 u |
| Change |
- ? |
|
| After |
1 p |
7 p |
Amount that Cathy had less than Eva
= 10 u - 3 u
= 7 u
7 u = 49
1 u = 49 ÷ 7 = 7
Amount that Cathy had at first
= 3 u
= 3 x 7
= $21
Amount that Eva had
= 10 u
= 10 x 7
= $70
The amount that Eva had at first and in the end remains the same.
10 u = 7 p
7 p = 70
1 p = 70 ÷ 7 = 10
Amount that Cathy had in the end
= 1 p
= $10
Amount that Cathy spent on the birthday present
= 21 - 10
= $11
Answer(s): $11
