The ratio of green to black stamps that Pamela had was 5 : 2. The cost of each of the green stamps was $4 and the cost of each of the black stamps was $9. Pamela sold 60% of the green stamps and the total cost of the unsold stamps was $104. How many green stamps did she have left?
| |
Green stamps |
Black stamps |
| Before |
5 u |
2 u |
| Change |
- 3 u |
|
| After |
2 u |
2 u |
Number of green stamps sold
= 60% x 5 u
=
60100 x 5 u
= 3 u
| |
Green stamps |
Black stamps |
Total |
| Number |
2 u |
2 u |
|
| Value |
$4 |
$9 |
|
| Total value |
8 u |
18 u |
$104 |
Total cost of unsold stamps
= 8 u + 18 u
= 26 u
26 u = 104
1 u = 104 ÷ 26 = 4
Number of green stamps that Pamela had left
= 8 u
= 8 x 4
= 32
Answer(s): 32
