The ratio of the number of red stickers to green stickers is 8 : 5. After Xavier gives away 10 red stickers and buys another 20 green stickers, there is equal number of red stickers and green stickers. How many stickers does Xavier have now?
| |
Red |
Green |
| Before |
8 u |
5 u |
| Change |
- 10 |
+ 20 |
| After |
8 u - 10 |
5 u + 20 |
The number of red stickers and green stickers in the end is the same.
8 u - 10 = 5 u + 20
8 u - 5 u = 20 + 10
3 u = 30
1 u = 30 ÷ 3 = 10
Number of stickers that Xavier has now
= 8 u - 10 + 5 u + 20
= 8 u + 5 u - 10 + 20
= 13 u + 10
= 13 x 10 + 10
= 130 + 10
= 140
Answer(s): 140
