The ratio of brown to red stamps that Gem had was 5 : 2. The cost of each of the brown stamps was $3 and the cost of each of the red stamps was $8. Gem sold 40% of the brown stamps and the total cost of the unsold stamps was $200. How many red stamps did she have left?
| |
Brown stamps |
Red stamps |
| Before |
5 u |
2 u |
| Change |
- 2 u |
|
| After |
3 u |
2 u |
Number of brown stamps sold
= 40% x 5 u
=
40100 x 5 u
= 2 u
| |
Brown stamps |
Red stamps |
Total |
| Number |
3 u |
2 u |
|
| Value |
$3 |
$8 |
|
| Total value |
9 u |
16 u |
$200 |
Total cost of unsold stamps
= 9 u + 16 u
= 25 u
25 u = 200
1 u = 200 ÷ 25 = 8
Number of red stamps that Gem had left
= 16 u
= 16 x 8
= 128
Answer(s): 128
