The speed of the river is 3 m / s, the speed of the motor boat is 5 m / s. How long does it take

The speed of the river is 3 m / s, the speed of the motor boat is 5 m / s. How long does it take for a fisherman to descend 80 m downstream?

A fisherman is sailing on a motorboat on the current, which means that his own
the speed of the boat and the speed of the river add up, so the current facilitates movement.
3 + 5 = 8 m / s – the total speed of the boat and the current
To find the time, you need to divide the distance by the speed:
80/8 = 10
10 c the fisherman was going downstream
Answer: 10 seconds