Howard, Will and Zeph had a total of 82 beads. The ratio of Will's beads to Zeph's beads was 6 : 7 at first. Howard and Will each gave away
12 of their beads. Given that the three boys had 62 beads left, how many beads did Howard have in the end?
|
Howard |
Will |
Zeph |
Total |
Comparing Will and Zeph at first |
|
6 u |
7 u |
|
Before |
2 p |
2x3 = 6 u |
7 u |
82 |
Change |
- 1 p |
-1x3 = - 3 u |
|
- 20 |
After |
1 p |
1x3 = 3 u |
7 u |
62 |
Total number of beads that Howard and Will gave away
= 82 - 62
= 20
The number of beads that Will had at first is repeated. Make the number of beads that Will had at first the same. LCM of 6 and 2 is 6.
1 p + 3 u = 82 - 62
1 p + 3 u = 20
1 p = 20 - 3 u --- (1)
1 p + 3 u + 7 u = 62
1 p + 10 u = 62
1 p = 62 - 10 u --- (2)
(1) = (2)
20 - 3 u = 62 - 10 u
10 u - 3 u = 62 - 20
10 u - 3 u = 42
7 u = 42
1 u = 42 ÷ 7 = 6
Substitute 1 u = 6 into (1).
1 p = 20 - 3 u
1 p = 20 - 3 x 6
1 p = 20 - 18
1 p = 2
Number of beads that Howard had in the end
= 1 p
= 2
Answer(s): 2