#### Answer

The column is compressed by 1.0 mm

#### Work Step by Step

We can use Young's modulus to solve this question:
$Y = \frac{F/A}{\Delta~L/L} = \frac{F~L}{A~\Delta L}$
For concrete, $Y = 30\times 10^9~N/m^2$
We then find the the distance $\Delta L$ that the column is compressed;
$Y = \frac{F~L}{A~\Delta L}$
$\Delta L = \frac{F~L}{A~Y}$
$\Delta L = \frac{(200,000~kg)(9.80~m/s^2)(3.0~m)}{(\pi)(0.25~m)^2~(30\times 10^9~N/m^2)}$
$\Delta L = 0.0010~m = 1.0~mm$
The column is compressed by 1.0 mm