The ratio of the number of red stickers to green stickers is 9 : 7.
After Adam gives away 90 red stickers and 20 green stickers,
there is an equal number of red stickers and green stickers.
How many stickers does Adam have now?
|
Red |
Green |
Before |
9 u |
7 u |
Change |
- 90 |
- 20 |
After |
9 u - 90 |
7 u - 20 |
The number of red stickers and green stickers in the end is the same.
9 u - 90 = 7 u - 20
9 u - 7 u = 90 - 20
2 u = 70
1 u = 70 ÷ 2 = 35
Number of stickers that Adam has now
= 9 u - 90 + 7 u - 20
= 9 u + 7 u - 90 - 20
= 16 u - 110
= 16 x 35 - 110
= 560 - 110
= 450
Answer(s): 450