Liam and John were given some allowances each. If Liam spent $13 each day and John spent $39 each day, Liam would still have $2432 left when John spent all his allowance. If Liam spent $39 each day and John spent $13 each day, Liam would still have $40 left when John spent all his allowance.
- How much allowance did Liam receive?
- How much allowance did John receive?
|
Case 1 |
Case 2 |
|
Liam |
John |
Liam |
John |
Before |
1 u + 2432 |
3 u |
3 p + 40 |
1 p |
Change |
- 1 u |
- 3 u |
- 3 p |
- 1 p |
After |
2432 |
0 |
40 |
0 |
(a)
Simplify the ratio.
13 : 39 = 1 : 3
The allowance that John had at first is the same for Case 1 and Case 2.
1 p = 3 u
3 p = 9 u
The allowance that Liam had at first is the same for Case 1 and Case 2.
9 u + 40 = 1 u + 2432
9 u - 1 u = 2432 - 40
8 u = 2392
1 u = 2392 ÷ 8 = 299
Allowance that Liam received
= 1 u + 2432
= 299 + 2432
= $2731
(b)
Allowance that John received
= 3 u
= 3 x 299
= $897
Answers: (a) $2731; (b) $897