Pierre, Flynn and Oscar had a total of 105 pens. The ratio of the number of pens that Flynn had to the number of pens that Oscar had was 4 : 5. After Pierre and Flynn each gave away half of their pens, the 3 children had 80 pens left. How many pens did Flynn and Oscar have in the end?
| |
Pierre |
Flynn |
Oscar |
Total |
| Before |
2 p |
4 u |
5 u |
105 |
| Change |
- 1 p |
- 2 u |
|
- 25 |
| After |
1 p |
2 u |
5 u |
80 |
Total number of pens that Pierre and Flynn gave away
= 105 - 80
= 25
1 p + 2 u = 25 --- (1)
1 p + 2 u + 5 u = 80
1 p + 7 u = 80 --- (2)
(2) - (1)
(1 p + 7 u) - (1 p + 2 u) = 80 - 25
7 u - 2 u = 55
5 u = 55
1 u = 55 ÷ 5 = 11
Total number of pens that Flynn and Oscar had in the end
= 2 u + 5 u
= 7 u
= 7 x 11
= 77
Answer(s): 77
