Ian and Billy have the same amount of money. If Ian spends $43 a day and Billy spends $14 a day, Billy will have $319 when Ian uses up all his money. If Ian spends $15 a day and Billy spends $43 a day, how much will Ian have left when Billy uses up all his money?
| |
Case 1 |
Case 2 |
| |
Ian |
Billy |
Ian |
Billy |
| Before |
43 u |
14 u + $319 |
43 u |
43 u |
| Change |
- 43 u |
- 14 u |
- 15 u |
- 43 u |
| After |
0 |
$319 |
28 u |
0 |
The amounts that Ian and Billy have at first are the same.
43 u = 14 u + 319
43 u - 14 u = 319
29 u = 319
1 u = 319 ÷ 29 = 11
Amount that Ian will have left when Billy uses up all his money
= 43 u - 15 u
= 28 u
= 28 x 11
= $308
Answer(s): $308
