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