Question

a motor boat whose speed is 18 km/h in still water takes 1 hour more
get 24km upstream than to return downstream to the same spot. Find the speed of
stream .​

Answer 1

Answer:

6km/hr

Step-by-step explanation:

Given parameters:

The speed of the motorboat in still water =18 kmph

Let us consider

The speed of the stream = s

Speed of boat upstream = Speed of a boat in still water – the speed of a stream

Speed of boat upstream = 18 – s

Speed of boat downstream = Speed of a boat in still water + speed of a stream

Speed of boat downstream = 18 + s

Time is taken for upstream = Time taken to cover downstream + 1

time =distance/speed

\frac{Distance_{upstream}}{Speed_{upstream}} = \frac{Distance_{downstream}}{Speed_{downstream}} + 1

24/ (18 – s) = [24/(18 + s)] + 1

24(18+s) = 24(18−s) + (18−s)(18+s)

s2 + 48s − 324 = 0

s2 + 54s − 6s − 324 = 0

(s+54)(s−6) = 0

s = 6,−54 but s ≠−54

Since the speed of steam cannot be negative.

∴ s = 6km/hr

Answer 2

Answer:

6 km\h

Step-by-step explanation:

speed of the stream is 6km\h