Andy, Oscar and Albert had a total of 128 beads. The ratio of the number of beads that Oscar had to the number of beads that Albert had was 4 : 9. After Andy and Oscar each gave away half of their beads, the 3 children had 100 beads left. How many beads did Oscar and Albert have in the end?
| |
Andy |
Oscar |
Albert |
Total |
| Before |
2 p |
4 u |
9 u |
128 |
| Change |
- 1 p |
- 2 u |
|
- 28 |
| After |
1 p |
2 u |
9 u |
100 |
Total number of beads that Andy and Oscar gave away
= 128 - 100
= 28
1 p + 2 u = 28 --- (1)
1 p + 2 u + 9 u = 100
1 p + 11 u = 100 --- (2)
(2) - (1)
(1 p + 11 u) - (1 p + 2 u) = 100 - 28
11 u - 2 u = 72
9 u = 72
1 u = 72 ÷ 9 = 8
Total number of beads that Oscar and Albert had in the end
= 2 u + 9 u
= 11 u
= 11 x 8
= 88
Answer(s): 88
