10 days ago, Risa had a total of 150 gold and grey stickers. 20% of her stickers were grey stickers. Today, her uncle gave her some more stickers. As a result, her gold stickers increased by 40%. Now, 50% of her stickers are grey stickers. How many grey stickers did her uncle give her?
| |
Grey stickers |
Gold stickers |
Total
stickers |
| Before |
1 u |
4 u |
150 |
| Change |
+ 4.6 u |
+ 1.6 u |
|
| After |
5.6 u |
5.6 u |
|
Comparing the
gold stickers and
grey stickers in the end |
1 |
1 |
|
20% =
20100 =
15 Grey stickers : Gold stickers = 1 : 4
Increase in the number of gold stickers
= 40% x 4 u
=
40100 x 4 u
= 1.6 u
50% =
50100 =
12 In the end
Grey stickers : Gold stickers = 1 : 1
Number of stickers at first
= 4 u + 1 u
= 5 u
5 u = 150
1 u = 150 ÷ 5 = 30
Number of grey stickers that Risa received from her uncle
= 5.6 u - 1 u
= 4.6 u
= 4.6 x 30
= 138
Answer(s): 138
