The ratio of the amount of money that Sabrina and Erika brought along was 3 : 4. For their sister's gift, Sabrina and Erika shared the cost in the ratio of 2 : 3. Sabrina used up
25 of her money to pay for her share. After paying for her share, Erika had $154 left. How much was the gift?
| |
Sabrina |
Erika |
| Before |
3 u |
4 u |
| Change |
- 1.2 u |
- 1.8 u |
Comparing the cost shared
between Sabrina and Erika |
- 2 p =
- 1.2 u |
- 3 p =
- 1.8 u |
| After |
1.8 u |
154 |
Amount that Sabrina spent on the gift
=
25 x 3 u
= 1.2 u
2 p = 1.2 u
1 p = 1.2 u ÷ 2 = 0.6
3 p = 3 x 0.6 = 1.8 u
Amount that Erika had left
= 4 u - 1.8 u
= 2.2 u
2.2 u = 154
1 u = 154 ÷ 2.2 = 70
Cost of the gift
= 1.2 u + 1.8 u
= 3 u
= 3 x 70
= $210
Answer: $210
