The ratio of gold to pink stamps that Yoko had was 5 : 3. The cost of each of the gold stamps was $4 and the cost of each of the pink stamps was $5. Yoko sold 60% of the gold stamps and the total cost of the unsold stamps was $161. How many gold stamps did she have left?
| |
Gold stamps |
Pink stamps |
| Before |
5 u |
3 u |
| Change |
- 3 u |
|
| After |
2 u |
3 u |
Number of gold stamps sold
= 60% x 5 u
=
60100 x 5 u
= 3 u
| |
Gold stamps |
Pink stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$4 |
$5 |
|
| Total value |
8 u |
15 u |
$161 |
Total cost of unsold stamps
= 8 u + 15 u
= 23 u
23 u = 161
1 u = 161 ÷ 23 = 7
Number of gold stamps that Yoko had left
= 8 u
= 8 x 7
= 56
Answer(s): 56
