The ratio of gold to black stamps that Linda had was 4 : 3. The cost of each of the gold stamps was $5 and the cost of each of the black stamps was $8. Linda sold 50% of the gold stamps and the total cost of the unsold stamps was $68. How many black stamps did she have left?
| |
Gold stamps |
Black stamps |
| Before |
4 u |
3 u |
| Change |
- 2 u |
|
| After |
2 u |
3 u |
Number of gold stamps sold
= 50% x 4 u
=
50100 x 4 u
= 2 u
| |
Gold stamps |
Black stamps |
Total |
| Number |
2 u |
3 u |
|
| Value |
$5 |
$8 |
|
| Total value |
10 u |
24 u |
$68 |
Total cost of unsold stamps
= 10 u + 24 u
= 34 u
34 u = 68
1 u = 68 ÷ 34 = 2
Number of black stamps that Linda had left
= 24 u
= 24 x 2
= 48
Answer(s): 48
