Adam has 60 red stickers and 130 green stickers.
After buying the same number of stickers,
the ratio of the red stickers and the green stickers becomes 3 : 5.
How many stickers does he buy?
|
Red |
Green |
Difference |
Before |
60 |
130 |
70 |
Change |
+ ? |
+ ? |
|
After |
3 u |
5 u |
2 u |
At first
Difference in the number of stickers
= 130 - 60
= 70
In the end
Number of red stickers = 3 u
Number of green stickers = 5 u
Difference in the number of stickers in units
= 5 u - 3 u
= 2 u
The difference in the number of stickers between the red stickers and the green stickers remains unchanged.
2 u = 70
1 u = 70 ÷ 2 = 35
Number of red stickers that Adam buys
= 3 u - 60
= 3 x 35 - 60
= 105 - 60
= 45
Total number of stickers that Adam buys
= 2 x 45
= 90
Answer(s): 90