The ratio of white to grey stamps that Yen had was 4 : 3. The cost of each of the white stamps was $2 and the cost of each of the grey stamps was $3. Yen sold 50% of the white stamps and the total cost of the unsold stamps was $104. How many white stamps did she have left?
| |
White stamps |
Grey stamps |
| Before |
4 u |
3 u |
| Change |
- 2 u |
|
| After |
2 u |
3 u |
Number of white stamps sold
= 50% x 4 u
=
50100 x 4 u
= 2 u
| |
White stamps |
Grey stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$2 |
$3 |
|
| Total value |
4 u |
9 u |
$104 |
Total cost of unsold stamps
= 4 u + 9 u
= 13 u
13 u = 104
1 u = 104 ÷ 13 = 8
Number of white stamps that Yen had left
= 4 u
= 4 x 8
= 32
Answer(s): 32
