Question

A man rows upstream 16km and down stream 28km, taking 5 hour each time, the velocity of the current?

• A. 2.4 km/hr
• B. 3.6 km/hr
• C. 1.2 km/hr
• D. 1.8 km/hr

Answer 1

Answer:

C. 1.2 km/hr

$$Let the Man speed be 'm'</p><p style="color: rgb(0,0,0); margin-top: 2px; margin-bottom: 2px" data-pxy="true">$$Speed of current be 'C'

$$Upstream Distance = 16 km</p><p style="color: rgb(0,0,0); margin-top: 2px; margin-bottom: 2px" data-pxy="true">$$Downstream Distance = 28 km

Time Taken Downstream,$=\frac{28}{(m+c)}=5hrs$

Time Taken Upstream, $=\frac{16}{(m-c)}=5hrs$

$$Subtracting Second equation from 1st one we get,

$10c=12$

$c=1.2$