The ratio of the number of red stickers to green stickers is 7 : 5.
After Adam gives away 90 red stickers and 60 green stickers,
there is an equal number of red stickers and green stickers.
How many stickers does Adam have now?
|
Red |
Green |
Before |
7 u |
5 u |
Change |
- 90 |
- 60 |
After |
7 u - 90 |
5 u - 60 |
The number of red stickers and green stickers in the end is the same.
7 u - 90 = 5 u - 60
7 u - 5 u = 90 - 60
2 u = 30
1 u = 30 ÷ 2 = 15
Number of stickers that Adam has now
= 7 u - 90 + 5 u - 60
= 7 u + 5 u - 90 - 60
= 12 u - 150
= 12 x 15 - 150
= 180 - 150
= 30
Answer(s): 30