One expression that Gary can use,where y is the amount of food eaten in a year and x the amount of food eaten in a weeks is:
y=x*52
but we actually know that the cats eat one third of 3 1/2 pounds, that is:
[tex] 3\frac{1}{2} * \frac{11}{2} = \frac{7*1}{2*2}= \frac{7}{4} [/tex]
So we can substitute this:
y=[tex] \frac{7}{4}*52 [/tex]
which is y=7*13=91
So we actually know that the cats eat 91 pounds of food a year!
