Question

A boat travels 24 km upstream in 6 h and 20 km downstream in 4 h. then, the speed of a boat in still water and the speed of current are respectively

A) 4.5 km/h and 3 km/h B) 4.5 km/h and 0.5 km/h C) 4 km/h and 2 km/h 5 km/h and 2 km/h D) 5 km/h and 2 km/h

Answer 1

Correct Answer:

B) 4.5 kmph and 0.5 kmph

Description for Correct answer:

Upstream speed, U

=246=123

= 4 km/h

Downstream speed, D

204

= 5 km/h

∴Speed of boat in still water, x

D+U2

=92= 4.5 km/h

Speed of water current, y

=D−U2=12

=0.5 km/h

Plz mark as brain list.

Answer 2

Answer:

Speed of boat upstream

= $\frac{24}{6}$

= 4 kmph

Speed of boat downstream

= $\frac{20}{4}$

= 5 kmph

∴ Speed in still water

= $\frac{4+5}{2}$

= 4.5 kmph

∴ Speed of the water current

=$\frac{5-4}{2}$

= 0.5 kmph

opition b) is the correct answer.