Adam and Bryan have $100.
Adam has 9 times as much money as Bryan.
How much must Adam give to Bryan
so Adam will have $80 less than Bryan?
|
Adam |
Bryan |
Total |
Before |
9 u |
1 u |
10 u |
Change |
- ? |
+ ? |
No change |
After |
$10 |
$10 + $80 |
$100 |
At first
Adam = 9 u
Bryan = 1 u
Total = 1 u + 9 u = 10 u
10 u = 100
1 u = 100 ÷ 10 = 10
Amount that Adam has at first
= 9 u
= 9 x 10
= $90
For Adam to have $80 less than Bryan in the end, we need to set aside $80 for Bryan before the remaining amount is divided into 2.
Amount that Adam will have in the end
= (100 - 80) ÷ 2
= 20 ÷ 2
= $10
Amount that Adam gives to Bryan
= Amount that Adam at first - Amount that Adam has in the end
= 90 - 10
= $80
Answer(s): $80