The ratio of purple to yellow stamps that Jaslyn had was 5 : 4. The cost of each of the purple stamps was $5 and the cost of each of the yellow stamps was $9. Jaslyn sold 20% of the purple stamps and the total cost of the unsold stamps was $616. How many purple stamps did she have left?
| |
Purple stamps |
Yellow stamps |
| Before |
5 u |
4 u |
| Change |
- 1 u |
|
| After |
4 u |
4 u |
Number of purple stamps sold
= 20% x 5 u
=
20100 x 5 u
= 1 u
| |
Purple stamps |
Yellow stamps |
Total |
| Number |
4 u |
4 u |
|
| Value |
$5 |
$9 |
|
| Total value |
20 u |
36 u |
$616 |
Total cost of unsold stamps
= 20 u + 36 u
= 56 u
56 u = 616
1 u = 616 ÷ 56 = 11
Number of purple stamps that Jaslyn had left
= 20 u
= 20 x 11
= 220
Answer(s): 220
