The capacity of the gas tank of the car is 90 liters. First, a tenth of the tank was filled, and then another

The capacity of the gas tank of the car is 90 liters. First, a tenth of the tank was filled, and then another 20 liters were filled. gasoline. How many liters of gasoline can I still fill in the gas tank?

Let’s denote the unknown number of liters, which is a tenth of the tank capacity, with the letter X.

Let’s compare in proportion 90 liters, as 10/10 of the total capacity, and X liters, as 1/10 of the total tank capacity.

Let’s make a proportion and find X:

90 liters – 10/10 of the total capacity;

X liters – make up 1/10 of the total capacity;

X = 90 * 1/10 = 9 liters.

Filled in 20 liters:

9 l + 20 l = 29 liters.

You can add more:

90 liters – 29 liters = 61 liters.

Answer: 61 liters of gasoline can still be poured into the tank.