The ratio of the number of green erasers to blue erasers is 5 : 3. After Glen gives away 10 green erasers and buys another 40 blue erasers, there is equal number of green erasers and blue erasers. How many erasers does Glen have now?
| |
Green |
Blue |
| Before |
5 u |
3 u |
| Change |
- 10 |
+ 40 |
| After |
5 u - 10 |
3 u + 40 |
The number of green erasers and blue erasers in the end is the same.
5 u - 10 = 3 u + 40
5 u - 3 u = 40 + 10
2 u = 50
1 u = 50 ÷ 2 = 25
Number of erasers that Glen has now
= 5 u - 10 + 3 u + 40
= 5 u + 3 u - 10 + 40
= 8 u + 30
= 8 x 25 + 30
= 200 + 30
= 230
Answer(s): 230
