The ratio of the number of green erasers to blue erasers is 8 : 3. After Bryan gives away 10 green erasers and buys another 80 blue erasers, there is equal number of green erasers and blue erasers. How many erasers does Bryan have now?
|
Green |
Blue |
Before |
8 u |
3 u |
Change |
- 10 |
+ 80 |
After |
8 u - 10 |
3 u + 80 |
The number of green erasers and blue erasers in the end is the same.
8 u - 10 = 3 u + 80
8 u - 3 u = 80 + 10
5 u = 90
1 u = 90 ÷ 5 = 18
Number of erasers that Bryan has now
= 8 u - 10 + 3 u + 80
= 8 u + 3 u - 10 + 80
= 11 u + 70
= 11 x 18 + 70
= 198 + 70
= 268
Answer(s): 268