Anna had
37 as much money as Tiffany. Anna had $36 less than Tiffany. Anna spent some money to buy a birthday present for her father. In the end, she had
19 as much money as Tiffany. How much did Anna spend on the birthday present?
| |
Anna |
Tiffany |
| Before |
3 u |
7 u |
| Change |
- ? |
|
| After |
1 p |
9 p |
Amount that Anna had less than Tiffany
= 7 u - 3 u
= 4 u
4 u = 36
1 u = 36 ÷ 4 = 9
Amount that Anna had at first
= 3 u
= 3 x 9
= $27
Amount that Tiffany had
= 7 u
= 7 x 9
= $63
The amount that Tiffany had at first and in the end remains the same.
7 u = 9 p
9 p = 63
1 p = 63 ÷ 9 = 7
Amount that Anna had in the end
= 1 p
= $7
Amount that Anna spent on the birthday present
= 27 - 7
= $20
Answer(s): $20
