Ahmad and Neave had some allowance in the ratio of 3 : 8. They shared some money to buy a necklace for their friend. The ratio of the amount paid by Ahmad to the amount paid by Neave was 1 : 3. If Neave was left with $20 and Ahmad had spent
23 of his money, how much was the necklace they bought?
| |
Ahmad |
Neave |
| Before |
3 u |
8 u |
| Change |
- 2 u |
- 6 u |
Comparing the
amounts spent |
- 1x2 |
- 3x2 |
| After |
1 u |
20 |
The amount that Ahmad spent is repeated. Make the amount that Ahmad spent the same. LCM of 1 and 2 is 2.
Amount that Ahmad spent
=
23 x 3 u
= 2 u
Amount that Neave spent
= 3 x 2 u
= 6 u
Amount that Neave had left
= 8 u - 6 u
= 2 u
2 u = 20
1 u = 20 ÷ 2 = 10
Price of the necklace
= 2 u + 6 u
= 8 u
= 8 x 10
= $80
Answer(s): $80
