A stone is dropped from top of a tower when it crosses a point 5 m below the top, another stone is let fall from a point 25 m below the top. Both stones reach the bottom of tower simultaneously. The height of tower is $(g=10 m/s^2)$

Question

$$(a)\;90\; m \quad (b)\;45 \;m \quad (c)\;35 \;m \quad(d)\;25\; m$$