The ratio of grey to silver stamps that Sarah had was 5 : 3. The cost of each of the grey stamps was $3 and the cost of each of the silver stamps was $8. Sarah sold 60% of the grey stamps and the total cost of the unsold stamps was $240. How many grey stamps did she have left?
| |
Grey stamps |
Silver stamps |
| Before |
5 u |
3 u |
| Change |
- 3 u |
|
| After |
2 u |
3 u |
Number of grey stamps sold
= 60% x 5 u
=
60100 x 5 u
= 3 u
| |
Grey stamps |
Silver stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$3 |
$8 |
|
| Total value |
6 u |
24 u |
$240 |
Total cost of unsold stamps
= 6 u + 24 u
= 30 u
30 u = 240
1 u = 240 ÷ 30 = 8
Number of grey stamps that Sarah had left
= 6 u
= 6 x 8
= 48
Answer(s): 48
