The ratio of yellow to green stamps that Xandra had was 5 : 2. The cost of each of the yellow stamps was $5 and the cost of each of the green stamps was $6. Xandra sold 40% of the yellow stamps and the total cost of the unsold stamps was $324. How many green stamps did she have left?
| |
Yellow stamps |
Green stamps |
| Before |
5 u |
2 u |
| Change |
- 2 u |
|
| After |
3 u |
2 u |
Number of yellow stamps sold
= 40% x 5 u
=
40100 x 5 u
= 2 u
| |
Yellow stamps |
Green stamps |
Total |
| Number |
3 u |
2 u |
|
| Value |
$5 |
$6 |
|
| Total value |
15 u |
12 u |
$324 |
Total cost of unsold stamps
= 15 u + 12 u
= 27 u
27 u = 324
1 u = 324 ÷ 27 = 12
Number of green stamps that Xandra had left
= 12 u
= 12 x 12
= 144
Answer(s): 144
