Twenty women together can complete a piece of work in 16 days, 16 men together can complete the same work in 15 days. The ratio of the working capacity of a man to that of a women is = ?

$$\eqalign{ & {\text{20 w}} \times {\text{16}} = {\text{16 m}} \times {\text{15}} \cr & {\text{20 w}} = {\text{15 m}} \cr & {\text{4 w}} = {\text{3 m}} \cr & \frac{{\text{m}}}{{\text{w}}} = \frac{4}{3} \cr & \therefore {\text{Man}}:{\text{Women}} \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,4:3 \cr} $$