3 days ago, Jaslyn had a total of 120 white and blue stamps. 30% of her stamps were blue stamps. Today, her auntie gave her some more stamps. As a result, her white stamps increased by 25%. Now, 50% of her stamps are blue stamps. How many blue stamps did her auntie give her?
| |
Blue stamps |
White stamps |
Total
stamps |
| Before |
3 u |
7 u |
120 |
| Change |
+ 5.75 u |
+ 1.75 u |
|
| After |
8.75 u |
8.75 u |
|
Comparing the
white stamps and
blue stamps in the end |
1 |
1 |
|
30% =
30100 =
310 Blue stamps : White stamps = 3 : 7
Increase in the number of white stamps
= 25% x 7 u
=
25100 x 7 u
= 1.75 u
50% =
50100 =
12 In the end
Blue stamps : White stamps = 1 : 1
Number of stamps at first
= 7 u + 3 u
= 10 u
10 u = 120
1 u = 120 ÷ 10 = 12
Number of blue stamps that Jaslyn received from her auntie
= 8.75 u - 3 u
= 5.75 u
= 5.75 x 12
= 69
Answer(s): 69
