According to Suresh solution :
Steps = 26 but speed of escalator cannot be (26-9) / 42.5 = 0.4
because Escalator always keep moving upwards...So if u r subtracting the number of steps the man climbed i.e 9 from 26, then you should also subtract the time taken by that man in climbing those steps from 42.5 secs
LEt the time taken by that man is t secs for climbing 9 steps
then speed of escalator will be (26 - 9) / (42.5 - t).