The traveler covered the distance equal to 800 km at the beginning by bus and then by train.

The traveler covered the distance equal to 800 km at the beginning by bus and then by train. he traveled by bus 300 less than by train. How many hours did the traveler travel if the speed of the bus was 50 km / h, and the speed of the train was 55 km / h.

To solve this problem, recall the formula for calculating the distance. Distance is equal to the product of time and speed. s = v * t, where s is distance, v is speed, t is time. Suppose the traveler traveled by bus – x km, then by train – (x + 300) km. Knowing. that the whole let 800 km. make an equation.
x + x + 300 = 800;
2x = 800-300;
2x = 500;
x = 500/2;
x = 250 km.
I traveled 250 km by bus, 250 + 300 = 550 km by train.
Let’s calculate how many hours the traveler traveled by bus if the bus speed is 50 km / h.
t1 = 250/50 = 5 hours.
Let’s calculate how many hours the traveler traveled by train if the train speed is 55 km / h.
t2 = 550/55 = 10 hours.
10 + 5 = 15 hours
Answer: 15 hours