Incorrect. Use the equation for work, $\displaystyle{r}=\frac{{W}}{{t}}\usepackage{cmbright}\Huge\$ , to relate the rates of the different lawnmowers: the rate of A is $\displaystyle\frac{{1}}{{4}}\usepackage{cmbright}\Huge\$ , the rate of B is $\displaystyle\frac{{1}}{{h}}\usepackage{cmbright}\Huge\$ , and the rate of C is $\displaystyle\frac{{1}}{{{3}{h}}}\usepackage{cmbright}\Huge\$ . If you add all these rates together, what should it be set equal to?