Solve this multiple-choice question and choose the correct option.

A man can row 6 km/h in still water. If the speed of the current is 2 km/h, it takes 3 h more in upstream than in the downstream for the same distance. The distance is?

30 km
24 km
20 km
32 km

Correct Answer: 24 km

Explanation:

Let total distance be x km. According to the question, x/(6 + 2) + 3 = x/6 - 2 ⇒ x/8 + 3 = x/4 ⇒ x/4 - x/8 = 3 ⇒ 2x - x/8 = 3 ∴ x = 8 x 3 = 24 km

More Questions from Boats and Streams

The speed of the current is 5 km/h. A motorboat goes 10 km upstream and back again to the starting point in 50 min. The speed, (in km/h) of the motorboat in still water is?
A boat cover a distance of 30 km downstream in 2 h while it takes 6 h to cover the same distance distance upstream. What is the speed of the boat (in km/h)?
A man can row at 10 km/h in still water. If he takes total 5 h to go to a place 24 km away and return, then the speed of the water current is?
Ashutosh can row at 24 km/h in still water. He takes twice as long to row a fixed distance upstream as he takes to row the same distance downstream. What is the speed of the stream (in km/h)?
A boat travels 12 km in 1 hour in still water (so v = 12 km/h). It takes three times as long to cover the same 12 km against the current. What is the speed of the current (in km/h)?
A boatman takes twice as long to row a fixed distance against the stream as he takes with the stream. Find the ratio of the boat speed in still water to the stream speed.
A river flows at 4 km/h. A rower goes downstream from the start to a turning point and then rows back upstream to the start. The total distance covered is 42 km (so each leg is 21 km). The upstream journey takes 2 hours more than the downstream journey. Find the rower speed in still water (km/h).
A river flows at 5 km/h. A swimmer can swim at 20 km/h in still water. He swims 30 km downstream from point A to point B, then immediately turns and swims 30 km upstream back to A. What is the total time taken?
Ishwar rows a boat. He takes half as much time to go a certain distance downstream as he takes to cover the same distance upstream. What is the ratio of the rate of the boat in still water to the rate of the current?
A man can row at 7.5 km/h in still water. The river current flows at 1.5 km/h. He rows from the start to a place and returns to the start in a total of 50 minutes. How far is the place from the start (one-way distance, in km)?

Discussion & Comments

No comments yet. Be the first to comment!