Speedboat speed downstream of the river 18.3 km / h and upstream 12.4.

Speedboat speed downstream of the river 18.3 km / h and upstream 12.4. What path along this river will a raft overcome in 4 hours?

First, let’s calculate the overall speed of the river.

1) 18.3 + 12.4 = 30.7 (km / h) – the total speed of the current.

Next, we calculate the speed with which the boat was moving.

2) 30.7: 2 = 15.35 (km / h) – speed of the boat.

Now we can calculate our own current speed.

3) 18.3 – 15.35 = 2.95 (km / h) is the proper current velocity.

Now we can answer the main question of the problem and calculate the number of kilometers that the raft will pass along the river in 4 hours.

4) 2.95 * 4 = 11.8 (kilometers) – raft in 4 hours.

Answer: the raft will cover 11.8 kilometers along the river in 4 hours.