Mark and Archie had some allowance in the ratio of 3 : 11. They shared some money to buy a necklace for their auntie. The ratio of the amount paid by Mark to the amount paid by Archie was 1 : 2. If Archie was left with $189 and Mark had spent
23 of his money, how much was the necklace they bought?
| |
Mark |
Archie |
| Before |
3 u |
11 u |
| Change |
- 2 u |
- 4 u |
Comparing the
amounts spent |
- 1x2 |
- 2x2 |
| After |
1 u |
189 |
The amount that Mark spent is repeated. Make the amount that Mark spent the same. LCM of 1 and 2 is 2.
Amount that Mark spent
=
23 x 3 u
= 2 u
Amount that Archie spent
= 2 x 2 u
= 4 u
Amount that Archie had left
= 11 u - 4 u
= 7 u
7 u = 189
1 u = 189 ÷ 7 = 27
Price of the necklace
= 2 u + 4 u
= 6 u
= 6 x 27
= $162
Answer(s): $162
