Erika had
47 as much money as Kathy. Erika had $42 less than Kathy. Erika spent some money to buy a birthday present for her niece. In the end, she had
12 as much money as Kathy. How much did Erika spend on the birthday present?
| |
Erika |
Kathy |
| Before |
4 u |
7 u |
| Change |
- ? |
|
| After |
1 p |
2 p |
Amount that Erika had less than Kathy
= 7 u - 4 u
= 3 u
3 u = 42
1 u = 42 ÷ 3 = 14
Amount that Erika had at first
= 4 u
= 4 x 14
= $56
Amount that Kathy had
= 7 u
= 7 x 14
= $98
The amount that Kathy had at first and in the end remains the same.
7 u = 2 p
2 p = 98
1 p = 98 ÷ 2 = 49
Amount that Erika had in the end
= 1 p
= $49
Amount that Erika spent on the birthday present
= 56 - 49
= $7
Answer(s): $7
