3 days ago, Sabrina had a total of 200 red and pink stamps. 40% of her stamps were pink stamps. Today, her mother gave her some more stamps. As a result, her red stamps increased by 30%. Now, 50% of her stamps are pink stamps. How many pink stamps did her mother give her?
| |
Pink stamps |
Red stamps |
Total
stamps |
| Before |
2 u |
3 u |
200 |
| Change |
+ 1.9 u |
+ 0.9 u |
|
| After |
3.9 u |
3.9 u |
|
Comparing the
red stamps and
pink stamps in the end |
1 |
1 |
|
40% =
40100 =
25 Pink stamps : Red stamps = 2 : 3
Increase in the number of red stamps
= 30% x 3 u
=
30100 x 3 u
= 0.9 u
50% =
50100 =
12 In the end
Pink stamps : Red stamps = 1 : 1
Number of stamps at first
= 3 u + 2 u
= 5 u
5 u = 200
1 u = 200 ÷ 5 = 40
Number of pink stamps that Sabrina received from her mother
= 3.9 u - 2 u
= 1.9 u
= 1.9 x 40
= 76
Answer(s): 76
