The ratio of the number of red stickers to blue stickers is 9 : 7.
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 |
9 u |
7 u |
Change |
- 80 |
- 20 |
After |
9 u - 80 |
7 u - 20 |
The number of red stickers and blue stickers in the end is the same.
9 u - 80 = 7 u - 20
9 u - 7 u = 80 - 20
2 u = 60
1 u = 60 ÷ 2 = 30
Number of stickers that Adam has now
= 9 u - 80 + 7 u - 20
= 9 u + 7 u - 80 - 20
= 16 u - 100
= 16 x 30 - 100
= 480 - 100
= 380
Answer(s): 380