...{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[\ C=3(F_{\mathrm{S}}+F_{\mathrm{B}})/w,\] \end{document} where F B is the buoyancy and w is the body weight of the beetles. The factor 3 was used to meet the condition that, during normal locomotion on the water surface, only three...