The ratio of brown to silver stamps that Usha had was 4 : 3. The cost of each of the brown stamps was $4 and the cost of each of the silver stamps was $9. Usha sold 50% of the brown stamps and the total cost of the unsold stamps was $140. How many brown stamps did she have left?
| |
Brown stamps |
Silver 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 |
Silver stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$4 |
$9 |
|
| Total value |
8 u |
27 u |
$140 |
Total cost of unsold stamps
= 8 u + 27 u
= 35 u
35 u = 140
1 u = 140 ÷ 35 = 4
Number of brown stamps that Usha had left
= 8 u
= 8 x 4
= 32
Answer(s): 32
