Let the length of the train be $$l$$ metre and speed of the train be $$x$$ m/s => $$frac{l}{s} = 18$$ => $$l = 18s$$ Also, $$frac{l + 300}{s} = 38$$ => $$18s + 300 = 38s$$ => $$20s = 300$$ => $$s = frac{300}{20} = 15$$ m/s $$ herefore$$ Speed of train in kmph = $$15 imes frac{18}{5}$$ = 54 kmph