The ratio of the number of green stickers to red stickers is 5 : 3. After Tim gives away 50 green stickers and buys another 90 red stickers, there is equal number of green stickers and red stickers. How many stickers does Tim have now?
| |
Green |
Red |
| Before |
5 u |
3 u |
| Change |
- 50 |
+ 90 |
| After |
5 u - 50 |
3 u + 90 |
The number of green stickers and red stickers in the end is the same.
5 u - 50 = 3 u + 90
5 u - 3 u = 90 + 50
2 u = 140
1 u = 140 ÷ 2 = 70
Number of stickers that Tim has now
= 5 u - 50 + 3 u + 90
= 5 u + 3 u - 50 + 90
= 8 u + 40
= 8 x 70 + 40
= 560 + 40
= 600
Answer(s): 600
