Calculate Flow Rate: Converting 20 Liters per 5 Minutes to Liters per Minute

The total volume of water that fills the tank is $20$ liters over $5$ minutes. The flow rate is given by the volume divided by time:
$\text{Flow Rate} = \frac{\text{Total Volume}}{\text{Time}} = \frac{20}{5} = 4$
Thus, the water flows at a rate of $4$ liters per minute.