A boat takes two hours to travel 8 km and come back in still water lake. If the velocity of water is 4 kmph the time taken for going upstream of 8 km and coming back is

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

2 hours 20 minutes

2 hours 40 minutes

1 hour 20 minutes

3 hours 30 minutes

answer is B.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Velocity of boat $v_{b} = \frac{8 + 8}{2} = 8 kmph$

Velocity of water $v_{w} = 4 kmph$

Up stream $d = (v_{b} - v_{w}) t_{1}$

$8 = 4 \times t_{1}$

$t_{1} = 2 h$

Down stream $d = (v_{b} - v_{w}) t_{2}$

$t_{2} = \frac{2}{3} h$

$= \frac{2}{3} \times 60 \min = 40 \min$

Total time T = 2hours 40 minutes

Watch 3-min video & get full concept clarity

JEE

NEET

Foundation JEE

Foundation NEET

CBSE