The ratio of brown to green stamps that Abi had was 4 : 3. The cost of each of the brown stamps was $4 and the cost of each of the green stamps was $7. Abi sold 50% of the brown stamps and the total cost of the unsold stamps was $261. How many green stamps did she have left?
| |
Brown stamps |
Green stamps |
| Before |
4 u |
3 u |
| Change |
- 2 u |
|
| After |
2 u |
3 u |
Number of brown stamps sold
= 50% x 4 u
=
50100 x 4 u
= 2 u
| |
Brown stamps |
Green stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$4 |
$7 |
|
| Total value |
8 u |
21 u |
$261 |
Total cost of unsold stamps
= 8 u + 21 u
= 29 u
29 u = 261
1 u = 261 ÷ 29 = 9
Number of green stamps that Abi had left
= 21 u
= 21 x 9
= 189
Answer(s): 189
