Rael and Charlie had some allowance in the ratio of 3 : 11. They shared some money to buy a necklace for their nephew. The ratio of the amount paid by Rael to the amount paid by Charlie was 1 : 3. If Charlie was left with $90 and Rael had spent
23 of his money, how much was the necklace they bought?
| |
Rael |
Charlie |
| Before |
3 u |
11 u |
| Change |
- 2 u |
- 6 u |
Comparing the
amounts spent |
- 1x2 |
- 3x2 |
| After |
1 u |
90 |
The amount that Rael spent is repeated. Make the amount that Rael spent the same. LCM of 1 and 2 is 2.
Amount that Rael spent
=
23 x 3 u
= 2 u
Amount that Charlie spent
= 3 x 2 u
= 6 u
Amount that Charlie had left
= 11 u - 6 u
= 5 u
5 u = 90
1 u = 90 ÷ 5 = 18
Price of the necklace
= 2 u + 6 u
= 8 u
= 8 x 18
= $144
Answer(s): $144
