The ratio of brown to pink stamps that Usha had was 4 : 3. The cost of each of the brown stamps was $5 and the cost of each of the pink stamps was $8. Usha sold 25% of the brown stamps and the total cost of the unsold stamps was $78. How many pink stamps did she have left?
| |
Brown stamps |
Pink stamps |
| Before |
4 u |
3 u |
| Change |
- 1 u |
|
| After |
3 u |
3 u |
Number of brown stamps sold
= 25% x 4 u
=
25100 x 4 u
= 1 u
| |
Brown stamps |
Pink stamps |
Total |
| Number |
3 u |
3 u |
|
| Value |
$5 |
$8 |
|
| Total value |
15 u |
24 u |
$78 |
Total cost of unsold stamps
= 15 u + 24 u
= 39 u
39 u = 78
1 u = 78 ÷ 39 = 2
Number of pink stamps that Usha had left
= 24 u
= 24 x 2
= 48
Answer(s): 48
