Adam has 30 red stickers and 90 green stickers.
After giving away the same number of stickers,
the ratio of the red stickers and the green stickers becomes 1 : 7.
How many stickers are given away?
|
Red |
Green |
Difference |
Before |
30 |
90 |
60 |
Change |
- ? |
- ? |
|
After |
1 u |
7 u |
6 u |
At first
Difference in the number of stickers
= 90 - 30
= 60
In the end
Difference in the number of stickers in units
= 7 u - 1 u
= 6 u
The difference in the number of stickers between the red stickers and the green stickers remains unchanged.
6 u = 60
1 u = 60 ÷ 6 = 10
Number of red stickers that Adam gives away
= 30 - 10
= 20
Total number of stickers that Adam gives away
= 2 x 20
= 40
Answer(s): 40