Andy, Nick and Jeremy had 81 coins. After Andy used 8 coins and Nick used
23 of her coins, Andy had thrice as many coins left as Nick. Jeremy bought another 17 coins, he had four times the number of coins Nick had left. How many coins did Jeremy have at first?
| |
Andy |
Nick |
Jeremy |
Total |
| Before |
3 u + 8 |
3 u |
4 u - 17 |
81 |
| Change |
- 8 |
- 2 u |
+ 17 |
|
| After |
3 u |
1 u |
4 u |
|
Comparing Andy
and Nick in the end |
3 |
1 |
|
|
Comparing Jeremy
and Nick in the end |
|
1 |
4 |
|
Number of coins that Andy had in the end
= 3 x 1 u
= 3 u
Number of coins that Jeremy had in the end
= 4 x 1 u
= 4 u
Total number of coins at first
= 3 u + 8 + 3 u + 4 u - 17
= 10 u - 9
10 u - 9 = 81
10 u = 81 + 9
10 u = 90
1 u = 90 ÷ 10 = 9
Number of coins that Jeremy had at first
= 4 u - 17
= 4 x 9 - 17
= 36 - 17
= 19
Answer(s): 19
