Find the time to move up when the escalator is standstill given the following conditions? Mr. X takes 30 seconds to go up by using "moving up" escalator and takes 120 seconds to come down using "moving up" escalator. Find the time to move up when the escalator is standstill.

MyApproach:

My Confusion is this Can I take the speed of the man and esclator to be x and y?

Because they are acting on the same body so
I applied relative velocity concept

I was doing t= D/(x+y)=$30$

Similarly, another equation would be t= D/(x-y)=$120$


  Am i right in my approach?Please correct me if I am wrong?
$\dfrac{x+y}{D} = \dfrac{1}{30}$, and $\dfrac{x-y}{D} = \dfrac{1}{120}$.

So what is $\dfrac{x}{D}$?
$\dfrac{x+y}{D} = \dfrac{1}{30}$, and $\dfrac{x-y}{D} = \dfrac{1}{120}$.

So what is $\dfrac{x}{D}$?