B moves by taking 3 steps forward and 1 step backward (each step in one second )He walks up a stationary escalator in 118 sec. However on moving escalator he takes 40 sec to reach top .Find speed of escalator.
option
a) 1step/sec
b) 2 step/sec
c) 3step/sec
d) 4step/sec

• first of all lets find d no. of steps for escalator.
  since first B moves 3 steps forward nd then 1 step backward so in total 4 seconds he moves only 2 steps forward so in 116 seconds he moves 58 steps forward now in next 2 seconds he moves 2 steps so in 118 seconds he moves total 60 steps forward.
  so no. of steps required to reach the top of the escalator is 60.
  now let d escalator moves a steps per second so in 4 seconds B moves 2 steps(3steps forward nd 1 step backward)in these 4 sec. escalator moves 4a step so in 4 sec. B moves a total of 2+4a step.
  so in 40 second total move=10*(2+4a)
  so, 10*(2+4a)=60
  hence a=1step/sec.
  ans iz a)1step/sec.
• 11 years agoHelpfull: Yes(55) No(6)
• effective speed of b is 2 steps per 4 sec
  => speed of b=1/2 steps per sec
  => total steps to be covered=x
  total time =118
  =>x=59 steps
  now let speed of escalator be y steps/sec
  =>59/(0.5+y)=40
  =>y = 1 step/sec(approx)
• 11 years agoHelpfull: Yes(18) No(7)
• B takes 2 steps in 4 sec => 118 sec he takes on stationary escalator
  116 sec he takes 58 steps : (116/4)*2=58
  left 2 sec he moves 2 steps so total steps is 58 +2 =60
  so B takes on moving escalator in 40 sec he takes 20 steps . therefore escalator moves
  60-20=40 steps . so speed is 40step/40 sec=1step /sec
• 9 years agoHelpfull: Yes(7) No(0)
• answer is 1, dont kno to explain properly
  
• 11 years agoHelpfull: Yes(1) No(14)
• answer is 4th option
• 11 years agoHelpfull: Yes(0) No(14)
• 40/59*118
  40/1*2
  40*2=80 steps
  so ans is 2 steps/sec.
• 11 years agoHelpfull: Yes(0) No(7)