SUPPOSE THE DISTANCE BETWEEN STATIONS =140KM

HENCE SPEED OF P =140/4 IE 35KMPH

SPEED OF Q =140/3.5 IE 40 KMPH

AGAIN SUPPOSE P MEET Q AFTER X HOURS AND Q MEET P AFTER X+2 HOURS(Q MAKES JOURNEY 2 HOURS EARLIER)

DISTANCE TRAVELED BY P =35X KM

DISTANCE TRAVELED BY Q =40(X+2) KM

35X+40(X+2) =140

SOLVING X =60/75 HRS

=60/75X60 MIUTES

=48 MINUTES

HENCE THE TWO TRAIN CROSS AT =9.48AM