Two motor boats move along the river in the same direction. The speed of the first boat is 18 km / h

Two motor boats move along the river in the same direction. The speed of the first boat is 18 km / h, the second is 27 km / h. How long will it take for the second boat to catch up with the first one if it departs from the pier 2 hours later than the first.

1. Find the distance the second boat travels more in 1 hour.
27 – 18 = 9 kilometers.
2. Let’s determine how many kilometers the first boat will move from the coast in 2 hours.
18 * 2 = 36 kilometers.
3. Find out how many hours the 2nd boat will be on the way before meeting the 1st boat.
36/9 = 4 hours.
Answer: After 4 hours the second motor boat will catch up with the first.