a) Suppose that the ratio cost:hours is constant; therefore,
[tex]\frac{15dollars}{3hours}=\frac{15}{3}\frac{dollars}{hours}=5\frac{dollars}{hours}[/tex]b) Similarly,
[tex]\frac{5acres}{43pounds}=\frac{5}{43}\frac{acres}{pound}\approx0.12\frac{acres}{pound}[/tex]