a motorboat whose speed is 18 kilometre in still water takes 1 hour 30 minutes more to go 36 km upstream then to return downstream to the same spot find the speed of the stream
Answers
Answer:
let speed of stream x km per h then
36/(18-x) -36/(18+x)=3/2
solving we get x= 6km per h
pls mark brainliest I'll follow u
Answer:
Step-by-step explanation:
Speed of boat in still water=18 km
Let speed of stream be x km/hr
Speed of boat upstream=speed of boat in still water-speed of stream
Speed of B.upstr.=(18+x) km/ur
Time of upstr. Journey/speed of boat upstr. =distance covered downst. /speed of the boat downst.
36/(18-x) =36/(18+x) +1 1/2hr
36/(18-x) -36/(18+x) =3/2
648+36x-648+36x/(18-x) (18+x) =3/2
72x=324-x²+3/2
x²+72x-324=3/2
x²+78x-6x-324=3/2
x(x+78) -6(x+78) =3/2
(x+78)(x-6) =3/2
x+78=3/2 Or x-6=3/2
x=--51/26km/hr Or x=15/2=7.5km/hr
Speed of stream cannot be in negative
So, speed of stream is 7.5km/hr
Plzzzz Mark it is the BRAINIEST answer of this question