Ten inches of snow is equivalent to about one inch of rain.1 Write an equation for the amount of precipitation, measured in inches of rain, r=f(s), as a function of the number of inches of snow, s.
Since "s / 10" gives "r", "r" could be replaced by 0.1s. This would result in "f(s) = 0.1s" as a function linking the two. 0.1 multiplied by the number of inches of snow would result in the number of inches of rain.