The ratio of the number of blue stickers to green stickers is 9 : 7.
After Adam gives away 30 blue stickers and 20 green stickers,
there is an equal number of blue stickers and green stickers.
How many stickers does Adam have now?
|
Blue |
Green |
Before |
9 u |
7 u |
Change |
- 30 |
- 20 |
After |
9 u - 30 |
7 u - 20 |
The number of blue stickers and green stickers in the end is the same.
9 u - 30 = 7 u - 20
9 u - 7 u = 30 - 20
2 u = 10
1 u = 10 ÷ 2 = 5
Number of stickers that Adam has now
= 9 u - 30 + 7 u - 20
= 9 u + 7 u - 30 - 20
= 16 u - 50
= 16 x 5 - 50
= 80 - 50
= 30
Answer(s): 30