Tommy, Jack and Liam had 320 coins. After Tommy used 9 coins and Jack used
15 of her coins, Tommy had thrice as many coins left as Jack. Liam bought another 19 coins, he had four times the number of coins Jack had left. How many coins did Liam have at first?
| |
Tommy |
Jack |
Liam |
Total |
| Before |
12 u + 9 |
5 u |
16 u - 19 |
320 |
| Change |
- 9 |
- 1 u |
+ 19 |
|
| After |
12 u |
4 u |
16 u |
|
Comparing Tommy
and Jack in the end |
3 |
1 |
|
|
Comparing Liam
and Jack in the end |
|
1 |
4 |
|
Number of coins that Tommy had in the end
= 3 x 4 u
= 12 u
Number of coins that Liam had in the end
= 4 x 4 u
= 16 u
Total number of coins at first
= 12 u + 9 + 5 u + 16 u - 19
= 33 u - 10
33 u - 10 = 320
33 u = 320 + 10
33 u = 330
1 u = 330 ÷ 33 = 10
Number of coins that Liam had at first
= 16 u - 19
= 16 x 10 - 19
= 160 - 19
= 141
Answer(s): 141
