The ratio of the number of red erasers to green erasers is 5 : 3. After Gabriel gives away 10 red erasers and buys another 40 green erasers, there is equal number of red erasers and green erasers. How many erasers does Gabriel have now?
| |
Red |
Green |
| Before |
5 u |
3 u |
| Change |
- 10 |
+ 40 |
| After |
5 u - 10 |
3 u + 40 |
The number of red erasers and green 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 Gabriel 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
