Passenger car for 75 km. and a freight truck for 140 km of track consumed together 27 liters of gasoline.

Passenger car for 75 km. and a freight truck for 140 km of track consumed together 27 liters of gasoline. Determine the consumption of gasoline by cars per 100 km. separately, if 1 km. the way the truck consumes 70 ml. more fuel than a passenger car.

Let us denote through the variable x the volume of fuel that a passenger car consumes per 100 km.
Therefore, a truck will consume (x + 0.07 * 100) per 100 kilometers.
Knowing that, under these conditions, their fuel consumption was 27 liters, we will draw up an equation and determine the consumption per 100 km for each type of car:
75x / 100 + 140 (x + 7) / 100 = 27;
75x + 140x = 2700 – 980;
215x = 1720;
x = 8;
8 + 7 = 15.
Answer: A passenger car consumes 8 liters per 100 km, and a truck consumes 15 liters.