Sam had $157 and his sister had $39 at first. After they received an equal amount of allowance, Sam had thrice as much money as his sister. How much allowance did each of them receive?
| |
Sam |
His sister |
Difference |
| Before |
$157 |
$39 |
$118 |
| Change |
+ ? |
+ ? |
|
| After |
3 u |
1 u |
2 u |
The difference in the amounts between Sam and his sister at first and in the end remains unchanged after each received an equal amount of allowance.
Difference in the amounts between Perry and his sister
= 3 u - 1 u
= 2 u
2 u = 157 - 39
2 u = 118
1 u = 118 ÷ 2 = 59
Allowance that each of them received
= 1 u - 39
= 59 - 39
= $20
Answer(s): $20
