Question

a boat travel 30km upstream in a river in a same oeriod of time as it take travel 50 km downstream. if the speed of the river current id 5kmph.find the speed of a boat in still water​

Answer 1

Answer:

20 kmph

Step-by-step explanation:

Let the speed of boat be ( x − 5 ) in upstream and ( x + 5 ) in downstream

s =  d/t

​ or t =  d/s

​ ⇒  30/5  = 6 hours and  

50/5   = 10 hours  

then the equation will be 6 ( x + 5 ) = 10 ( x − 5 )

6x + 30 = 10x − 50

⇒ 10x − 6x = 30 + 50

⇒ 4x = 80

⇒ x =  80/4

​  =20

speed of the boat in still water is 20 kmph