The ratio of blue to green stamps that Fiona had was 5 : 2. The cost of each of the blue stamps was $4 and the cost of each of the green stamps was $9. Fiona sold 60% of the blue stamps and the total cost of the unsold stamps was $104. How many green stamps did she have left?
| |
Blue stamps |
Green stamps |
| Before |
5 u |
2 u |
| Change |
- 3 u |
|
| After |
2 u |
2 u |
Number of blue stamps sold
= 60% x 5 u
=
60100 x 5 u
= 3 u
| |
Blue stamps |
Green 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 Fiona had left
= 18 u
= 18 x 4
= 72
Answer(s): 72
