Question

8. A boat takes 2 hours to go 10 km and come back
in still water lake. The time taken for going 10 km
upstream and coming back with water velocity of
5 km/h is :
(1) 140 min
(2) 150 min
(3) 160 min
(4) 170 min​

Answer 1

Answer:

hey the ans can be 60 mins but there is mistake in option I think because speed of boat in still water is 5 km /hr and water velocity =5 so time t = (10(1/5-5 [upstream] 1/ 5+5 [down stram ].

so all total time is 1 hr so 60 mins

Answer 2

Answer:

Time taken for covering 10km= 2 hours

So distance covered in 1 hour=5km

Total distance covered =20km

Time taken - 140min