The ratio of the amount of money that Olivia and Kimberly brought along was 3 : 4. For their brother's present, Olivia and Kimberly shared the cost in the ratio of 3 : 2. Olivia used up
35 of her money to pay for her share. After paying for her share, Kimberly had $84 left. How much was the present?
| |
Olivia |
Kimberly |
| Before |
3 u |
4 u |
| Change |
- 1.8 u |
- 1.2 u |
Comparing the cost shared
between Olivia and Kimberly |
- 3 p =
- 1.8 u |
- 2 p =
- 1.2 u |
| After |
1.2 u |
84 |
Amount that Olivia spent on the present
=
35 x 3 u
= 1.8 u
3 p = 1.8 u
1 p = 1.8 u ÷ 3 = 0.6
2 p = 2 x 0.6 = 1.2 u
Amount that Kimberly had left
= 4 u - 1.2 u
= 2.8 u
2.8 u = 84
1 u = 84 ÷ 2.8 = 30
Cost of the present
= 1.8 u + 1.2 u
= 3 u
= 3 x 30
= $90
Answer: $90
