The ratio of yellow to gold stamps that Lucy had was 5 : 4. The cost of each of the yellow stamps was $4 and the cost of each of the gold stamps was $8. Lucy sold 20% of the yellow stamps and the total cost of the unsold stamps was $144. How many gold stamps did she have left?
|
Yellow stamps |
Gold stamps |
Before |
5 u |
4 u |
Change |
- 1 u |
|
After |
4 u |
4 u |
Number of yellow stamps sold
= 20% x 5 u
=
20100 x 5 u
= 1 u
|
Yellow stamps |
Gold stamps |
Total |
Number |
4 u |
4 u |
|
Value |
$4 |
$8 |
|
Total value |
16 u |
32 u |
$144 |
Total cost of unsold stamps
= 16 u + 32 u
= 48 u
48 u = 144
1 u = 144 ÷ 48 = 3
Number of gold stamps that Lucy had left
= 32 u
= 32 x 3
= 96
Answer(s): 96