Given:
An apartment building caretaker puts 650 ml of chlorine into the swimming pool every day.
For 30 days the supply of chlorine the caretaker needs is,
[tex]\begin{gathered} 30\times650\text{ ml} \\ =19500\text{ ml} \end{gathered}[/tex]In litres,
[tex]\frac{19500ml}{1000}=19.5\text{ litre}[/tex]Answer: 19.5 litres
