Question

A boat moves downstream at the rate of one km in 10 minutes and upstream at the rate of 4 km an hour. What is the velocity of current ?

Answer 1

Given,

velocity of boat in downstream = 1km/10 min.

Therefore,

velocity of boat per hour=1*6=6km/hr.

Let the velocity of boat be x km/hr and that of current be y km/hr.

Therefore, velocity of boat in upstream=x-y km/hr.

Velocity of boat in downstream =x+y km/hr.

x+y=6

x-y=4

Therefore, 2x=10

Or, x=5

x+y=6

Or, y=6-5=1

Therefore, speed of current =y km/hr

=1 km/hr(ans)