Question

the speed of a motor boat in still water is a 25 km/hr .in a river, it goes 60km downstream and come back the same distance upstream in 5 hours. find the speed of the current.​

Answer 1

Answer:

c)25 km/h

Step-by-step explanation:

Let speed of boat be x km/h.

Given speed of current = 5 km/h

Therefore, Upstream speed of boat = (x-5) km/h

Downstream speed of boat = (x + 5) km/h

According to the question,

10

x−5

+

10

x+5

=

50

60

10(

x+5+x−5

x2−25

)=

5

6

12×2x=x2−25

x2−24x−25=0

x2−25x+x−25=0

(x−25)(x+1)=0

Therefore, x = 25 [because,x≠−1]

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