Comparing rates: i kinda need with the whole

[1] Amount of water per minute
Water Miser:  m = 3.0 gal/min
Watersaver:   m = 2.5 gal/min
Waterstream: m = 1.5 gal/min

[2] Equations:
I would suggest using y = mx.
Water Miser:  y = 3x
Watersaver:   y = 2.5x
Waterstream: y = 1.5x

[3] For 6,8,10, and 12 minutes:
Plug in x = 6, x = 8, x = 10, and x = 12 into each of the three equations and record the y-values.

[4] Which would you buy?
Depends on your personal opinion.

Want to save the earth? Pick the one that uses the least amount of water.

Want to have a waterfall for a shower? Pick the one that uses the most amount of water. :)

A. is the answer in this question