Risa had $30 more than Gabby at first. After Risa and Gabby spent an equal amount of money, Gabby had
710 as much as Risa. How much money did Risa have left?
| |
Risa |
Gabby |
Difference |
| Before |
1 u + $30 |
1 u |
$30 |
| Change |
- 1 |
- 1 |
|
| After |
10 p |
7 p |
3 p |
Difference in the amounts between Risa and Gabby
= 10 p - 7 p
= 3 p
Since both Risa and Gabby spent an equal amount, the difference in the amounts that Risa and Gabby had at first and in the end remains unchanged.
3 p = 30
1 p = 30 ÷ 3 = 10
Amount that Risa had left
= 10 p
= 10 x 10
= $100
Answer(s): $100
