Riordan and Eric had some allowance in the ratio of 5 : 9. They shared some money to buy a ring for their friend. The ratio of the amount paid by Riordan to the amount paid by Eric was 1 : 2. If Eric was left with $75 and Riordan had spent
35 of his money, how much was the ring they bought?
| |
Riordan |
Eric |
| Before |
5 u |
9 u |
| Change |
- 3 u |
- 6 u |
Comparing the
amounts spent |
- 1x3 |
- 2x3 |
| After |
2 u |
75 |
The amount that Riordan spent is repeated. Make the amount that Riordan spent the same. LCM of 1 and 3 is 3.
Amount that Riordan spent
=
35 x 5 u
= 3 u
Amount that Eric spent
= 2 x 3 u
= 6 u
Amount that Eric had left
= 9 u - 6 u
= 3 u
3 u = 75
1 u = 75 ÷ 3 = 25
Price of the ring
= 3 u + 6 u
= 9 u
= 9 x 25
= $225
Answer(s): $225
