Paul, Cole and Jack had a total of 110 coins. The ratio of the number of coins that Cole had to the number of coins that Jack had was 4 : 9. After Paul and Cole each gave away half of their coins, the 3 children had 91 coins left. How many coins did Cole and Jack have in the end?
| |
Paul |
Cole |
Jack |
Total |
| Before |
2 p |
4 u |
9 u |
110 |
| Change |
- 1 p |
- 2 u |
|
- 19 |
| After |
1 p |
2 u |
9 u |
91 |
Total number of coins that Paul and Cole gave away
= 110 - 91
= 19
1 p + 2 u = 19 --- (1)
1 p + 2 u + 9 u = 91
1 p + 11 u = 91 --- (2)
(2) - (1)
(1 p + 11 u) - (1 p + 2 u) = 91 - 19
11 u - 2 u = 72
9 u = 72
1 u = 72 ÷ 9 = 8
Total number of coins that Cole and Jack had in the end
= 2 u + 9 u
= 11 u
= 11 x 8
= 88
Answer(s): 88
