Charlie, Elijah and Ryan had a total of 42 beads. The ratio of Elijah's beads to Ryan's beads was 6 : 5 at first. Charlie and Elijah each gave away
12 of their beads. Given that the three boys had 26 beads left, how many beads did Charlie have in the end?
|
Charlie |
Elijah |
Ryan |
Total |
Comparing Elijah and Ryan at first |
|
6 u |
5 u |
|
Before |
2 p |
2x3 = 6 u |
5 u |
42 |
Change |
- 1 p |
-1x3 = - 3 u |
|
- 16 |
After |
1 p |
1x3 = 3 u |
5 u |
26 |
Total number of beads that Charlie and Elijah gave away
= 42 - 26
= 16
The number of beads that Elijah had at first is repeated. Make the number of beads that Elijah had at first the same. LCM of 6 and 2 is 6.
1 p + 3 u = 42 - 26
1 p + 3 u = 16
1 p = 16 - 3 u --- (1)
1 p + 3 u + 5 u = 26
1 p + 8 u = 26
1 p = 26 - 8 u --- (2)
(1) = (2)
16 - 3 u = 26 - 8 u
8 u - 3 u = 26 - 16
8 u - 3 u = 10
5 u = 10
1 u = 10 ÷ 5 = 2
Substitute 1 u = 2 into (1).
1 p = 16 - 3 u
1 p = 16 - 3 x 2
1 p = 16 - 6
1 p = 10
Number of beads that Charlie had in the end
= 1 p
= 10
Answer(s): 10