The ratio of the number of red stickers to blue stickers is 7 : 5.
After Adam gives away 90 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 |
5 u |
Change |
- 90 |
- 20 |
After |
7 u - 90 |
5 u - 20 |
The number of red stickers and blue stickers in the end is the same.
7 u - 90 = 5 u - 20
7 u - 5 u = 90 - 20
2 u = 70
1 u = 70 ÷ 2 = 35
Number of stickers that Adam has now
= 7 u - 90 + 5 u - 20
= 7 u + 5 u - 90 - 20
= 12 u - 110
= 12 x 35 - 110
= 420 - 110
= 310
Answer(s): 310