The ratio of the number of red stickers to green stickers is 3 : 1. After Glen gives away 60 red stickers and buys another 90 green stickers, there is equal number of red stickers and green stickers. How many stickers does Glen have now?
|
Red |
Green |
Before |
3 u |
1 u |
Change |
- 60 |
+ 90 |
After |
3 u - 60 |
1 u + 90 |
The number of red stickers and green stickers in the end is the same.
3 u - 60 = 1 u + 90
3 u - 1 u = 90 + 60
2 u = 150
1 u = 150 ÷ 2 = 75
Number of stickers that Glen has now
= 3 u - 60 + 1 u + 90
= 3 u + 1 u - 60 + 90
= 4 u + 30
= 4 x 75 + 30
= 300 + 30
= 330
Answer(s): 330