A truck left point A at a speed of 60 km / h. Two hours later, a passenger car followed her from point A

A truck left point A at a speed of 60 km / h. Two hours later, a passenger car followed her from point A at a speed of 90 km / h. How many hours after its departure the car will catch up with the truck.

1. Find out how far the truck will travel in 2 hours if its speed is 60 km per hour.
60 * 2 = 120 km.
2. Suppose that a passenger car will catch up with a truck in x hours, then the distance that the truck will travel for the entire time will be 120 + 60 * x km.
3. Let’s find out what distance a passenger car will travel, if its speed is 90 km per hour, it is equal to 90 * x km.
4. Let’s write down the equation and find out how many hours it will take for a car to catch up with the truck, if they eventually traveled the same distance.
120 + 60 * x = 90 * x;
120 = 90 * x – 60 * x;
120 = 30 * x;
x = 120/30;
x = 4 hours.