The ratio of white to grey stamps that Winnie had was 5 : 4. The cost of each of the white stamps was $2 and the cost of each of the grey stamps was $5. Winnie sold 60% of the white stamps and the total cost of the unsold stamps was $96. How many grey stamps did she have left?
|
White stamps |
Grey stamps |
Before |
5 u |
4 u |
Change |
- 3 u |
|
After |
2 u |
4 u |
Number of white stamps sold
= 60% x 5 u
=
60100 x 5 u
= 3 u
|
White stamps |
Grey stamps |
Total |
Number |
2 u |
4 u |
|
Value |
$2 |
$5 |
|
Total value |
4 u |
20 u |
$96 |
Total cost of unsold stamps
= 4 u + 20 u
= 24 u
24 u = 96
1 u = 96 ÷ 24 = 4
Number of grey stamps that Winnie had left
= 20 u
= 20 x 4
= 80
Answer(s): 80