Cathy and Kylie had equal amount of money. Each day, Cathy spent $5 and Kylie spent $10. When Cathy had $120 left, Kylie had
78 as much money left as Cathy. How much money did the two girls have at first?
| |
Cathy |
Kylie |
| Before |
5 u + 120 |
10 u + 105 |
| Change |
- 5 u |
- 10 u |
| After |
$120 |
$105 |
Amount that Kylie had left
=
78 x 120
= $105
The amount that Cathy and Kylie had at first is the same.
10 u + 105 = 5 u + 120
10 u - 5 u = 120 - 105
5 u = 15
1 u = 15 ÷ 5 = 3
Amount that Cathy had at first
= 5 u + 120
= 5 x 3 + 120
= 15 + 120
= $135
Total amount that both girls had at first
= 2 x 135
= $270
Answer(s): $270
