The ratio of blue to brown stamps that Lynn had was 5 : 2. The cost of each of the blue stamps was $2 and the cost of each of the brown stamps was $5. Lynn sold 20% of the blue stamps and the total cost of the unsold stamps was $54. How many blue stamps did she have left?
|
Blue stamps |
Brown stamps |
Before |
5 u |
2 u |
Change |
- 1 u |
|
After |
4 u |
2 u |
Number of blue stamps sold
= 20% x 5 u
=
20100 x 5 u
= 1 u
|
Blue stamps |
Brown stamps |
Total |
Number |
4 u |
2 u |
|
Value |
$2 |
$5 |
|
Total value |
8 u |
10 u |
$54 |
Total cost of unsold stamps
= 8 u + 10 u
= 18 u
18 u = 54
1 u = 54 ÷ 18 = 3
Number of blue stamps that Lynn had left
= 8 u
= 8 x 3
= 24
Answer(s): 24