Howard, Flynn and Bobby had a total of 131 erasers. The ratio of the number of erasers that Flynn had to the number of erasers that Bobby had was 4 : 7. After Howard and Flynn each gave away half of their erasers, the 3 children had 104 erasers left. How many erasers did Flynn and Bobby have at first?
| |
Howard |
Flynn |
Bobby |
Total |
| Before |
2 p |
4 u |
7 u |
131 |
| Change |
- 1 p |
- 2 u |
|
- 27 |
| After |
1 p |
2 u |
7 u |
104 |
Total number of erasers that Howard and Flynn gave away
= 131 - 104
= 27
1 p + 2 u = 27 --- (1)
1 p + 2 u + 7 u = 104
1 p + 9 u = 104 --- (2)
(2) - (1)
(1 p + 9 u) - (1 p + 2 u) = 104 - 27
9 u - 2 u = 77
7 u = 77
1 u = 77 ÷ 7 = 11
Total number of erasers that Flynn and Bobby had at first
= 4 u + 7 u
= 11 u
= 11 x 11
= 121
Answer(s): 121
