Speed of a boat in standing water is 9 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at… · ABC26GN3818
Subject: General Aptitude · Chapter: Boats and Streams
Speed of a boat in standing water is 9 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is :
(a)16 hours
(b)18 hours
(c)20 hours
(d)24 hours
Answer
Answer (as printed): D
Explanation
Speed upstream $=7.5 \mathrm{kmph}$; Speed downstream $=10.5$ kmph. $$\text { ∴ } \text { Total time taken }=\left(\frac{105}{7.5}+\frac{105}{10.5}\right) \text { hours }=24 \text { hours. }$$
Explanation as extracted from the printed page; notation may be imperfect.