Question

6. A motor boat whose speed is 15 km/hr in still water goes 30 km down stream and comes ba
of 4 hours 30 minutes. Determine the speed of the stream.
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Answer 1

Answer:

5km/hr

Step-by-step explanation:

Let the speed of stream be x km/hr

Now during downstream

time consumed will be 30/(15+x)

and time consumed in upstream will be

30/(15-x)

total time given in hours is 4.5 hours

30/(15+x) + 30/(15-x) = 4.5

450-30x +450 +30 x = 4.5(225-x^2)

900/4.5= 225 - x^2

solving above we will get

x=5

answer is 5km/hr