The distance between berths A and B is at least 56 km. The tourists sailed on a motor boat from berth A

The distance between berths A and B is at least 56 km. The tourists sailed on a motor boat from berth A to B and back in 3 hours 45 minutes, the boat’s own speed is 30 km / hour, and the river’s speed is 2 km / hour. How long did it take for tourists to sail downstream from pier A to pier B?

1. Determine with what speed the boat was sailing downstream:

30 + 2 = 32 km / h.

2. Find out how long the tourists were sailing from pier A to pier B:

56: 32 = 1.75 hours or 1 hour 45 minutes (0.75 * 60 = 45 minutes, in 1 hour 60 minutes).

Then they swam upstream for 2 hours (3 hours 45 minutes – 1 hour 45 minutes, or 30 – 2 = 28 km / h, 56:28 = 2 hours).

Answer: in 1 hour 45 minutes, the tourists swam downstream from pier A to pier B.