10 days ago, Kylie had a total of 280 blue and red stickers. 25% of her stickers were red stickers. Today, her younger brother gave her some more stickers. As a result, her blue stickers increased by 30%. Now, 50% of her stickers are red stickers. How many red stickers did her younger brother give her?
| |
Red stickers |
Blue stickers |
Total
stickers |
| Before |
1 u |
3 u |
280 |
| Change |
+ 2.9 u |
+ 0.9 u |
|
| After |
3.9 u |
3.9 u |
|
Comparing the
blue stickers and
red stickers in the end |
1 |
1 |
|
25% =
25100 =
14 Red stickers : Blue stickers = 1 : 3
Increase in the number of blue stickers
= 30% x 3 u
=
30100 x 3 u
= 0.9 u
50% =
50100 =
12 In the end
Red stickers : Blue stickers = 1 : 1
Number of stickers at first
= 3 u + 1 u
= 4 u
4 u = 280
1 u = 280 ÷ 4 = 70
Number of red stickers that Kylie received from her younger brother
= 3.9 u - 1 u
= 2.9 u
= 2.9 x 70
= 203
Answer(s): 203
