If a bathtub is being filled at a rate of 2.5 gallons per minute, how long will it take to fill the bathtub?

You need say how big the bathtub it is or you cant do it.

type the rest and ill try to answer it

Let x = number of minutes

( 2.5 liters/min )*(x) = 30 liters

         x = (30 liters) / (2.5 liters/min)

         x = 30/2.5 min      [note how liters cancel]

         x = 12 min

Check:

 Is  2.5*12 = 30   ?

       30 = 30   ?yes