The ratio of the number of red stickers to blue stickers is 9 : 7.
After Adam gives away 90 red stickers and 60 blue stickers,
there is an equal number of red stickers and blue stickers.
How many stickers does Adam have now?
|
Red |
Blue |
Before |
9 u |
7 u |
Change |
- 90 |
- 60 |
After |
9 u - 90 |
7 u - 60 |
The number of red stickers and blue stickers in the end is the same.
9 u - 90 = 7 u - 60
9 u - 7 u = 90 - 60
2 u = 30
1 u = 30 ÷ 2 = 15
Number of stickers that Adam has now
= 9 u - 90 + 7 u - 60
= 9 u + 7 u - 90 - 60
= 16 u - 150
= 16 x 15 - 150
= 240 - 150
= 90
Answer(s): 90