A man takes 2.2 times as long to row a distance upstream as to row the same distance downstream. If he can row 55 km downstream in 2 hour 30 minutes, what is the speed of the boat in the still water?

A man takes 2.2 times as long to row a distance upstream as to row the same distance downstream. If he can row 55 km downstream in 2 hour 30 minutes, what is the speed of the boat in the still water? Correct Answer 16 km/h

$$\eqalign{ & {\text{Speed of the boat in downstream }} \cr & {\text{ = }}\frac{{55}}{{2.5}} = \frac{{55 \times 10}}{{25}} = 22\,km/hr \cr & {\text{Then, speed of the boat in upstream}} \cr & {\text{ = }}\frac{{22}}{{2.2}} = \frac{{22 \times 10}}{{22}} = 10\,km/hr \cr & \therefore {\text{Speed of the boat in still water}} \cr & {\text{ = }}\frac{{22 + 10}}{2} = 16\,km/hr \cr} $$

Related Questions

In the following question, three statements are given. You have to find which is/are necessary and sufficient to answer the following question. Find the speed of the boat in still water. Statement I: The boat goes twice the distance downstream in the same time, as it goes upstream. Statement II: Speed of the boat in still water is three times the speed of the current. Statement III: The boat goes 840 meters in 1 hour 10 minutes downstream.
The following questions have three statements. Study the question and the statements and decide which of the statement(s) is/are necessary to answer the question. Find the speed of the boat in still water. Statement I: The boat goes twice the distance downstream as it goes upstream in 30 minutes. Statement II: The boat goes 720 meters in 1 hour downstream. Statement III: Speed of the boat in still water is three times the speed of the current.