The ratio of gold to red stamps that Jen had was 5 : 2. The cost of each of the gold stamps was $5 and the cost of each of the red stamps was $8. Jen sold 20% of the gold stamps and the total cost of the unsold stamps was $216. How many red stamps did she have left?
| |
Gold stamps |
Red stamps |
| Before |
5 u |
2 u |
| Change |
- 1 u |
|
| After |
4 u |
2 u |
Number of gold stamps sold
= 20% x 5 u
=
20100 x 5 u
= 1 u
| |
Gold stamps |
Red stamps |
Total |
| Number |
4 u |
2 u |
|
| Value |
$5 |
$8 |
|
| Total value |
20 u |
16 u |
$216 |
Total cost of unsold stamps
= 20 u + 16 u
= 36 u
36 u = 216
1 u = 216 ÷ 36 = 6
Number of red stamps that Jen had left
= 16 u
= 16 x 6
= 96
Answer(s): 96
