The ratio of blue to silver stamps that Sarah had was 4 : 3. The cost of each of the blue stamps was $4 and the cost of each of the silver stamps was $8. Sarah sold 50% of the blue stamps and the total cost of the unsold stamps was $160. How many silver stamps did she have left?
| |
Blue stamps |
Silver stamps |
| Before |
4 u |
3 u |
| Change |
- 2 u |
|
| After |
2 u |
3 u |
Number of blue stamps sold
= 50% x 4 u
=
50100 x 4 u
= 2 u
| |
Blue stamps |
Silver stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$4 |
$8 |
|
| Total value |
8 u |
24 u |
$160 |
Total cost of unsold stamps
= 8 u + 24 u
= 32 u
32 u = 160
1 u = 160 ÷ 32 = 5
Number of silver stamps that Sarah had left
= 24 u
= 24 x 5
= 120
Answer(s): 120
