The ratio of the number of red stickers to blue stickers is 7 : 2.
After Adam gives away 80 red stickers and 20 blue stickers,
there is an equal number of red stickers and blue stickers.
How many stickers does Adam have now?
|
Red |
Blue |
Before |
7 u |
2 u |
Change |
- 80 |
- 20 |
After |
7 u - 80 |
2 u - 20 |
The number of red stickers and blue stickers in the end is the same.
7 u - 80 = 2 u - 20
7 u - 2 u = 80 - 20
5 u = 60
1 u = 60 ÷ 5 = 12
Number of stickers that Adam has now
= 7 u - 80 + 2 u - 20
= 7 u + 2 u - 80 - 20
= 9 u - 100
= 9 x 12 - 100
= 108 - 100
= 8
Answer(s): 8