a motor boat whose speed is 15km/hr in still water goes 30km downstream nd comes back in a total of 4hrs 30mins.the speed of d stream(in km/hr) is (a)4 (b)5 (c)6 (d)10

• Let speed of stream be x
  speed of boat in still water=15kmph
  speed of boat for downstream=15+x
  speed of boat for upstream=15-x
  time=distance/speed
  implies 30/(15+x)+30/(15-x)=9/2
  225-x^2=200
  x^2=25
  x=5
• 12 years agoHelpfull: Yes(5) No(0)
• 12.54 km/hr
  
• 12 years agoHelpfull: Yes(0) No(2)