Vincent and Ian were given some allowances each. If Vincent spent $21 each day and Ian spent $42 each day, Vincent would still have $987 left when Ian spent all his allowance. If Vincent spent $42 each day and Ian spent $21 each day, Vincent would still have $42 left when Ian spent all his allowance.
- How much allowance did Vincent receive?
- How much allowance did Ian receive?
|
Case 1 |
Case 2 |
|
Vincent |
Ian |
Vincent |
Ian |
Before |
1 u + 987 |
2 u |
2 p + 42 |
1 p |
Change |
- 1 u |
- 2 u |
- 2 p |
- 1 p |
After |
987 |
0 |
42 |
0 |
(a)
Simplify the ratio.
21 : 42 = 1 : 2
The allowance that Ian had at first is the same for Case 1 and Case 2.
1 p = 2 u
2 p = 4 u
The allowance that Vincent had at first is the same for Case 1 and Case 2.
4 u + 42 = 1 u + 987
4 u - 1 u = 987 - 42
3 u = 945
1 u = 945 ÷ 3 = 315
Allowance that Vincent received
= 1 u + 987
= 315 + 987
= $1302
(b)
Allowance that Ian received
= 2 u
= 2 x 315
= $630
Answers: (a) $1302; (b) $630