ANSWER
15 minutes per meter
Step-by-step explanation
To find the unit rate in minutes per meter, we have to divide the number of minutes it takes to fill 2/5 meters of the tank by 2/5 meters:
Using the KCF method:
Keep the first fraction - which in this case has a denominator of 1
Change the division sign into a multiplication sign
Flip the second fraction
And then do the multiplication:
And simplify:
So the unit rate is 15 minutes per meter