Word Problem

VIDEOTAPES
A VHS videocassette contains 800 feet of tape.  In the long play mode (LP), it plays 10 feet of tape every 3 minutes.  Write a linear equation that relates the number of feet "f" of tape yet to be played and the number of minutes "m" the tape has been playing.

I've been staring at this damn word problem for about 15 minutes and don't really know were the hell to start with it.  Anyone able to show me how to work this out?

In prefix order, for clarity. each of the functions (= - * /) are bindary; the variables and constants (f 800 m 10 3)take no arguments.

= f - 800 * m / 10 3

Hope that helps.