Sam and Elijah had some allowance in the ratio of 3 : 10. They shared some money to buy a ring for their auntie. The ratio of the amount paid by Sam to the amount paid by Elijah was 1 : 2. If Elijah was left with $120 and Sam had spent
23 of his money, how much was the ring they bought?
| |
Sam |
Elijah |
| Before |
3 u |
10 u |
| Change |
- 2 u |
- 4 u |
Comparing the
amounts spent |
- 1x2 |
- 2x2 |
| After |
1 u |
120 |
The amount that Sam spent is repeated. Make the amount that Sam spent the same. LCM of 1 and 2 is 2.
Amount that Sam spent
=
23 x 3 u
= 2 u
Amount that Elijah spent
= 2 x 2 u
= 4 u
Amount that Elijah had left
= 10 u - 4 u
= 6 u
6 u = 120
1 u = 120 ÷ 6 = 20
Price of the ring
= 2 u + 4 u
= 6 u
= 6 x 20
= $120
Answer(s): $120
