A bicycle rider went a mile in three minutes with the wind, and returned in four minutes against the wind. How fast could he ride a mile if there was no wind?

• let cycle speed only= x,
  wind speed only=y
  same directn speed= x+y
  opp. directn speed= x-y
  he travelled 1 mile.
  so 1/(x+y)=3
  &
  1/(x-y)=5
  s0 x comes out to be= 8/30 mile/min.
  so he take 30/8= 3.75 min when no wind is there.
• 12 years agoHelpfull: Yes(0) No(2)
• let speed with wind be a=3
  speed against wind be b=4
  speed=1/2(a+b)
  i.e 3.5 is the ans
• 9 years agoHelpfull: Yes(0) No(0)
• let the rider move at "u"miles per minute and let the wind blow at "v"miles per minute .
  velocity of bicycle rider with the wind is "u+v"=1/3 miles/mminute
  velocity of bicycle rider against the wind is "u-v"=1/4 miles/minute
  
  
  
  solving the two equations
  
  u+v=1/3
  u-v=1/4
  we get u=7/24
  i.e speed of rider when there is no wind is [7/24]miles/minute
  therefore he could ride a mile in 17.5 seconds i.e [7/24]miles/minute
• 9 years agoHelpfull: Yes(0) No(0)