7 days ago, Lynn had a total of 200 silver and gold stamps. 25% of her stamps were gold stamps. Today, her cousin gave her some more stamps. As a result, her silver stamps increased by 10%. Now, 50% of her stamps are gold stamps. How many gold stamps did her cousin give her?
| |
Gold stamps |
Silver stamps |
Total
stamps |
| Before |
1 u |
3 u |
200 |
| Change |
+ 2.3 u |
+ 0.3 u |
|
| After |
3.3 u |
3.3 u |
|
Comparing the
silver stamps and
gold stamps in the end |
1 |
1 |
|
25% =
25100 =
14 Gold stamps : Silver stamps = 1 : 3
Increase in the number of silver stamps
= 10% x 3 u
=
10100 x 3 u
= 0.3 u
50% =
50100 =
12 In the end
Gold stamps : Silver stamps = 1 : 1
Number of stamps at first
= 3 u + 1 u
= 4 u
4 u = 200
1 u = 200 ÷ 4 = 50
Number of gold stamps that Lynn received from her cousin
= 3.3 u - 1 u
= 2.3 u
= 2.3 x 50
= 115
Answer(s): 115
