Below is a picture of a liquid soap kitchen dispenser Mr Mothapo installed in his kitchen. Study the diagram and answer the questions that follow.

The diameter of the dispenser is given as 54 mm. The radius is half of the diameter.

To convert millimeters (mm) to centimeters (cm), we divide by 10.

The radius of the dispenser is $\boxed{\text{2.7 cm}}$.

The formula for the volume of a cylinder is $V = \pi r^2 h$.
From the diagram, the height of the main dispenser body is 150 mm.
From Step 1, the radius $r = 27 \text{ mm}$.
We are given $\pi = 3.142$.

To convert cubic millimeters ($\text{mm}^3$) to millilitres (ml), we use the conversion 1 ml = 1000 $\text{mm}^3$.

Rounding to the nearest millilitre:

The capacity of the dispenser is $\boxed{\text{344 ml}}$.

The capacity of one dispenser is 344 ml (from Step 2).
The total volume of liquid soap is 20 litres. First, convert litres to millilitres (1 L = 1000 ml).

Now, divide the total volume by the capacity of one dispenser:

Since you can only fill whole dispensers, we round down to the nearest whole number.
The number of dispensers that can be filled is $\boxed{\text{58}}$.

The problem states the dispenser head is open at the bottom and provides the formula for the surface area of a cylinder as $\pi r^2 + 2 \pi r h$. This formula includes one circular base ($\pi r^2$) and the