Question

A MOTOR BOAT whose speed is
18KM/h in still water takes
1hr more to go 24 km upstream
to return down streams to the
Same spot, find the speed of stream​

Answer 1

Step-by-step explanation:

Given:

Speed of boat in still water = 18km/hr

Let speed of the stream = s

Speed of boat upstream = Speed of boat in still water - speed of stream = 18−s

Speed of boat down stream = Speed of boat in still water + speed of stream = 18+s

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

⇒

Speed

upstream

Distance

upstream

=

Speed

downstream

Distance

downstream

+1

⇒

18−s

24

=

18+s

24

+1

⇒24(18+s)=24(18−s)+(18−s)(18+s)

⇒s

2

+48s−324=0

⇒s

2

+54s−6s−324=0

⇒(s+54)(s−6)=0

⇒s=6,−54

⇒s



=−54

Thus, s=6km/hr, Speed of steam cannot be negative.