Flynn and Gabriel had some pens in the ratio of 7 : 5. Gabriel and Eric had some pens in the ratio of 2 : 1. Flynn sold 81 pens to Eric and ended up with half the number of pens Gabriel had. How many pens did Eric have in the end?
| Flynn |
Gabriel |
Eric |
| 7x2 |
5x2 |
|
| |
2x5 |
1x5 |
| 14 u |
10 u |
5 u |
The number of pens that Gabriel had at first is repeated. Make the number of pens that Gabriel had at first the same. LCM of 5 and 2 is 10.
| |
Flynn |
Gabriel |
Eric |
| Before |
14 u |
10 u |
5 u |
| Change |
- 81 |
|
+ 81 |
| After |
5 u |
10 u |
5 u + 81 |
Number of pens that Flynn had in the end
= 10 u ÷ 2
= 5 u
Number of pens that Flynn sold to Eric
= 14 u - 5 u
= 9 u
9 u = 81
1 u = 81 ÷ 9 = 9
Number of pens that Eric had in the end
= 5 u + 81
= 5 x 9 + 81
= 45 + 81
= 126
Answer(s): 126
