Question 167572
lets call S the number of steps on the escalator:the escalator is moving 

with Leon, so we must add the number of steps taken by Leon to the # of steps when it is still. d=rt so lets call d in this instance S+28 and S+40.  time is 28 sec in 1st scenario and 20 sec in the 2nd instance(40/2).

S+28=r(28)
S+40=r(20)

solve the system:

subtract the 2nd equation from the 1st to eliminate the S terms

-12=8r---->r=-3/2--->now plug r's value into either equation I choose the 2nd equation

S+40=(-3/2)20
S+40=-30
{{{highlight(S=70)}}}feet on the escalator when still