Question

A man can row 5 kmph in still water. If the river is running at 1 kmph, it takes him 75 minutes to row to a place and back. How far is the place?

• A. 3 km
• B. 2.5 km
• C. 4 km
• D. 5 km

Answer 1

The correct option is A 3 km

Speed downstream = (5 + 1) km/hr = 6 km/hr

Speed upstream = (5 - 1) km/hr = 4 km/hr

Let the required distance be x km
Then, $\frac{x}{6}+\frac{x}{4}=\frac{75}{60}or,2x+3x=15orx=3.$

$\therefore$ Required distance = 3 km.