The speed of a boat in still water is 17 km/hr and the speed of the stream is 16 km/hr. A man rows to a place at a distance of 26.4 km and comes back to the starting point. Find the total time (in hours) taken by him.​

Correct option is D

Given:

Speed of the boat in still water (x) = 17 km/hr

Speed of the stream (y) = 16 km/hr

Distance to the place (d) = 26.4 km

Formula Used:

Downstream speed = x + y (speed of the boat when moving downstream with the current)

Upstream speed = x - y (speed of the boat when moving upstream against the current)

Time = $$\frac{\text{Distance}}{\text{Speed}}$$​​

Solution:

Downstream speed = x + y = 17 + 16 = 33 km/hr

Upstream speed = x - y = 17 - 16 = 1 km/hr

Time downstream = $$\frac{26.4}{33} = 0.8 \, \text{hours}$$​​

Time upstream = $$\frac{26.4}{1} = 26.4 \, \text{hours}$$​​

Total time = 0.8 + 26.4 = 27.2 hours