Adam has 40 red stickers and 60 green stickers.
After giving away the same number of stickers,
the ratio of the red stickers and the green stickers becomes 1 : 3.
How many stickers are given away?
|
Red |
Green |
Difference |
Before |
40 |
60 |
20 |
Change |
- ? |
- ? |
|
After |
1 u |
3 u |
2 u |
At first
Difference in the number of stickers
= 60 - 40
= 20
In the end
Difference in the number of stickers in units
= 3 u - 1 u
= 2 u
The difference in the number of stickers between the red stickers and the green stickers remains unchanged.
2 u = 20
1 u = 20 ÷ 2 = 10
Number of red stickers that Adam gives away
= 40 - 10
= 30
Total number of stickers that Adam gives away
= 2 x 30
= 60
Answer(s): 60