Perry and Bobby were given some allowances each. If Perry spent $13 each day and Bobby spent $39 each day, Perry would still have $3158 left when Bobby spent all his allowance. If Perry spent $39 each day and Bobby spent $13 each day, Perry would still have $38 left when Bobby spent all his allowance.
- How much allowance did Perry receive?
- How much allowance did Bobby receive?
|
Case 1 |
Case 2 |
|
Perry |
Bobby |
Perry |
Bobby |
Before |
1 u + 3158 |
3 u |
3 p + 38 |
1 p |
Change |
- 1 u |
- 3 u |
- 3 p |
- 1 p |
After |
3158 |
0 |
38 |
0 |
(a)
Simplify the ratio.
13 : 39 = 1 : 3
The allowance that Bobby had at first is the same for Case 1 and Case 2.
1 p = 3 u
3 p = 9 u
The allowance that Perry had at first is the same for Case 1 and Case 2.
9 u + 38 = 1 u + 3158
9 u - 1 u = 3158 - 38
8 u = 3120
1 u = 3120 ÷ 8 = 390
Allowance that Perry received
= 1 u + 3158
= 390 + 3158
= $3548
(b)
Allowance that Bobby received
= 3 u
= 3 x 390
= $1170
Answers: (a) $3548; (b) $1170