The ratio of the number of red stickers to green stickers is 7 : 5. After Fabian gives away 30 red stickers and buys another 40 green stickers, there is equal number of red stickers and green stickers. How many stickers does Fabian have now?
| |
Red |
Green |
| Before |
7 u |
5 u |
| Change |
- 30 |
+ 40 |
| After |
7 u - 30 |
5 u + 40 |
The number of red stickers and green stickers in the end is the same.
7 u - 30 = 5 u + 40
7 u - 5 u = 40 + 30
2 u = 70
1 u = 70 ÷ 2 = 35
Number of stickers that Fabian has now
= 7 u - 30 + 5 u + 40
= 7 u + 5 u - 30 + 40
= 12 u + 10
= 12 x 35 + 10
= 420 + 10
= 430
Answer(s): 430
