Emily, Cindy and Sarah had a total of 174 buttons. The ratio of Cindy's buttons to Sarah's buttons was at first 8 : 5. After Emily and Cindy each gave half of their buttons away, the 3 children had 112 buttons left. How many buttons did Emily and Cindy have at first?
|
Emily |
Cindy |
Sarah |
Total |
Before |
2 p |
8 u |
5 u |
174 |
Change |
- 1 p |
- 4 u |
|
- 62 |
After |
1 p |
4 u |
5 u |
112 |
Number of buttons that Emily and Cindy gave away
= 174 - 112
= 62
1 p + 4 u = 62
1 p = 62 - 4 u --- (1)
1 p + 4 u + 5 u = 112
1 p + 9 u = 112
1 p = 112 - 9 u --- (2)
(1) = (2)
62 - 4 u = 112 - 9 u
9 u - 4 u = 112 - 62
5 u = 50
1 u = 50 ÷ 5 = 10
From (1)
1 p = 62 - 4 u
1 p = 62 - 4 x 10
1 p = 62 - 40 = 22
Number of buttons that Emily and Cindy had at first
= 2 p + 8 u
= 2 x 22 + 8 x 10
= 44 + 50
= 94
Answer(s): 94