Riordan and Flynn had some allowance in the ratio of 5 : 8. They shared some money to buy a necklace for their cousin. The ratio of the amount paid by Riordan to the amount paid by Flynn was 1 : 2. If Flynn was left with $68 and Riordan had spent
25 of his money, how much was the necklace they bought?
| |
Riordan |
Flynn |
| Before |
5 u |
8 u |
| Change |
- 2 u |
- 4 u |
Comparing the
amounts spent |
- 1x2 |
- 2x2 |
| After |
3 u |
68 |
The amount that Riordan spent is repeated. Make the amount that Riordan spent the same. LCM of 1 and 2 is 2.
Amount that Riordan spent
=
25 x 5 u
= 2 u
Amount that Flynn spent
= 2 x 2 u
= 4 u
Amount that Flynn had left
= 8 u - 4 u
= 4 u
4 u = 68
1 u = 68 ÷ 4 = 17
Price of the necklace
= 2 u + 4 u
= 6 u
= 6 x 17
= $102
Answer(s): $102
