John and Liam were given some allowances each. If John spent $30 each day and Liam spent $90 each day, John would still have $1475 left when Liam spent all his allowance. If John spent $90 each day and Liam spent $30 each day, John would still have $35 left when Liam spent all his allowance.
- How much allowance did John receive?
- How much allowance did Liam receive?
|
Case 1 |
Case 2 |
|
John |
Liam |
John |
Liam |
Before |
1 u + 1475 |
3 u |
3 p + 35 |
1 p |
Change |
- 1 u |
- 3 u |
- 3 p |
- 1 p |
After |
1475 |
0 |
35 |
0 |
(a)
Simplify the ratio.
30 : 90 = 1 : 3
The allowance that Liam had at first is the same for Case 1 and Case 2.
1 p = 3 u
3 p = 9 u
The allowance that John had at first is the same for Case 1 and Case 2.
9 u + 35 = 1 u + 1475
9 u - 1 u = 1475 - 35
8 u = 1440
1 u = 1440 ÷ 8 = 180
Allowance that John received
= 1 u + 1475
= 180 + 1475
= $1655
(b)
Allowance that Liam received
= 3 u
= 3 x 180
= $540
Answers: (a) $1655; (b) $540