Katrina walks down an up-escalator and counts 150 steps. Priyanka walks up the same escalator and counts 75 steps. Katrina takes three times as many steps in a given time as Priyanka. How many steps are visible on the escalator?
Options:
A . 105
B . 150
C . 135
D . 120
E . none of these
Answer: Option D : D Total steps are constant. Taking speed of Katrina to Priyanka to escalator as 3:1:x ⇒150−(1503)×x=75+(751)×x⇒150−50x=75+75x⇒75=125x⇒x=35 So steps =15−1503×35=120
