To find the rate of change of water in the tanker per minute, we can use the information provided:
The tanker drains 24 gallons of water in 6 minutes.
To find the rate per minute, we can divide the total gallons drained by the total time in minutes:
\[ \text{Rate} = \frac{\text{Gallons drained}}{\text{Time (minutes)}} = \frac{24 \text{ gallons}}{6 \text{ minutes}} = 4 \text{ gallons per minute} \]
So, the changing water in 1 minute is 4 gallons.