Answer:
- 675 litres
- 80 mL
Explanation:
1. The total amount of oil in the two tanks at the start is ...
total oil = n + (n +150) + 0 = 2n+150 . . . . litres
The amount of oil in tank C at the end is 1/3 this amount, or
oil in tank C = (total oil)/3 = (2n+150)/3 . . . . litres
The amount pumped into tank C was 500 litres, so we have ...
(2n +150)/3 = 500
2n +150 = 1500 . . . . . . multiply by 3
2n = 1350 . . . . . . . . . . . subtract 150
1350/2 = n = 675 . . . . . divide by the coefficient of n
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2. Let x represent the amount remaining in container A. Then 4x is the amount in tank B. Before the transfer, the amount in each container was the same, so ...
x +120 = 4x -120 . . . . . A had 120 more than remains; B had 120 less
240 = 3x . . . . . . . . add 120-x
240/3 = x = 80 . . . divide by the coefficient of x
The amount of liquid left in container A is 80 mL.