Question

If we know the height of of a building and length of steps the how we will find how many steps qre there

Answer 1

i suppose you mean height of the steps is known,then no. of steps that will fit in the building is
$no.of \: steps = \frac{height \: of \: building}{height \: of \: one \: step}$
if you actually meant length of step then there is no way to find the number of steps that will fit inside the building