The ratio of the amount of money that Lynn and Cathy brought along was 4 : 5. For their sister's present, Lynn and Cathy shared the cost in the ratio of 3 : 2. Lynn used up
35 of her money to pay for her share. After paying for her share, Cathy had $170 left. How much was the present?
| |
Lynn |
Cathy |
| Before |
4 u |
5 u |
| Change |
- 2.4 u |
- 1.6 u |
Comparing the cost shared
between Lynn and Cathy |
- 3 p =
- 2.4 u |
- 2 p =
- 1.6 u |
| After |
1.6 u |
170 |
Amount that Lynn spent on the present
=
35 x 4 u
= 2.4 u
3 p = 2.4 u
1 p = 2.4 u ÷ 3 = 0.8
2 p = 2 x 0.8 = 1.6 u
Amount that Cathy had left
= 5 u - 1.6 u
= 3.4 u
3.4 u = 170
1 u = 170 ÷ 3.4 = 50
Cost of the present
= 2.4 u + 1.6 u
= 4 u
= 4 x 50
= $200
Answer: $200
