The ratio of green to white stamps that Tiffany had was 5 : 2. The cost of each of the green stamps was $2 and the cost of each of the white stamps was $7. Tiffany sold 20% of the green stamps and the total cost of the unsold stamps was $88. How many white stamps did she have left?
| |
Green stamps |
White stamps |
| Before |
5 u |
2 u |
| Change |
- 1 u |
|
| After |
4 u |
2 u |
Number of green stamps sold
= 20% x 5 u
=
20100 x 5 u
= 1 u
| |
Green stamps |
White stamps |
Total |
| Number |
4 u |
2 u |
|
| Value |
$2 |
$7 |
|
| Total value |
8 u |
14 u |
$88 |
Total cost of unsold stamps
= 8 u + 14 u
= 22 u
22 u = 88
1 u = 88 ÷ 22 = 4
Number of white stamps that Tiffany had left
= 14 u
= 14 x 4
= 56
Answer(s): 56
