The ratio of the number of green stickers to red stickers is 3 : 1. After George gives away 10 green stickers and buys another 90 red stickers, there is equal number of green stickers and red stickers. How many stickers does George have now?
|
Green |
Red |
Before |
3 u |
1 u |
Change |
- 10 |
+ 90 |
After |
3 u - 10 |
1 u + 90 |
The number of green stickers and red stickers in the end is the same.
3 u - 10 = 1 u + 90
3 u - 1 u = 90 + 10
2 u = 100
1 u = 100 ÷ 2 = 50
Number of stickers that George has now
= 3 u - 10 + 1 u + 90
= 3 u + 1 u - 10 + 90
= 4 u + 80
= 4 x 50 + 80
= 200 + 80
= 280
Answer(s): 280