Ian, Wesley and Perry had a total of 60 beads. The ratio of Wesley's beads to Perry's beads was 4 : 7 at first. Ian and Wesley each gave away
12 of their beads. Given that the three boys had 44 beads left, how many beads did Ian have in the end?
|
Ian |
Wesley |
Perry |
Total |
Comparing Wesley and Perry at first |
|
4 u |
7 u |
|
Before |
2 p |
2x2 = 4 u |
7 u |
60 |
Change |
- 1 p |
-1x2 = - 2 u |
|
- 16 |
After |
1 p |
1x2 = 2 u |
7 u |
44 |
Total number of beads that Ian and Wesley gave away
= 60 - 44
= 16
The number of beads that Wesley had at first is repeated. Make the number of beads that Wesley had at first the same. LCM of 4 and 2 is 4.
1 p + 2 u = 60 - 44
1 p + 2 u = 16
1 p = 16 - 2 u --- (1)
1 p + 2 u + 7 u = 44
1 p + 9 u = 44
1 p = 44 - 9 u --- (2)
(1) = (2)
16 - 2 u = 44 - 9 u
9 u - 2 u = 44 - 16
9 u - 2 u = 28
7 u = 28
1 u = 28 ÷ 7 = 4
Substitute 1 u = 4 into (1).
1 p = 16 - 2 u
1 p = 16 - 2 x 4
1 p = 16 - 8
1 p = 8
Number of beads that Ian had in the end
= 1 p
= 8
Answer(s): 8