Answer
The height between the basement and the seventh floor is $23.0~m$
Work Step by Step
Let $P_1$ be the pressure on the seventh floor and let $P_2$ be the pressure in the basement. We can use Bernoulli's equation to find the height difference $h$:
$P_1+\rho~g~h = P_2$
$h = \frac{P_2-P_1}{\rho~g}$
$h = \frac{(4.10\times 10^5~Pa)-(1.85\times 10^5~Pa)}{(1000~kg/m^3)(9.80~m/s^2)}$
$h = 23.0~m$
The height between the basement and the seventh floor is $23.0~m$.
