The ratio of the number of green pens to blue pens is 8 : 3. After Luis gives away 30 green pens and buys another 80 blue pens, there is equal number of green pens and blue pens. How many pens does Luis have now?
| |
Green |
Blue |
| Before |
8 u |
3 u |
| Change |
- 30 |
+ 80 |
| After |
8 u - 30 |
3 u + 80 |
The number of green pens and blue pens in the end is the same.
8 u - 30 = 3 u + 80
8 u - 3 u = 80 + 30
5 u = 110
1 u = 110 ÷ 5 = 22
Number of pens that Luis has now
= 8 u - 30 + 3 u + 80
= 8 u + 3 u - 30 + 80
= 11 u + 50
= 11 x 22 + 50
= 242 + 50
= 292
Answer(s): 292
