
$\frac{(\text { stress })_{\mathrm{u}}}{(\text { stress })_{\ell}}=\frac{\left(\mathrm{m}_{\mathrm{u}}+\mathrm{m}_{\ell}\right) \mathrm{g} / \mathrm{A}_{\mathrm{u}}}{\left(\mathrm{m}_{\ell}\right) \mathrm{g} / \mathrm{A}_{\ell}}$
$=\frac{\left(\mathrm{d}_{\mathfrak{u}} \mathrm{A}_{\mathfrak{u}} \mathrm{L}_{\mathfrak{u}}+\mathrm{d}_{\ell} \mathrm{A}_{\ell} \mathrm{L}_{\ell}\right) / \mathrm{A}_{\mathfrak{u}}}{\left(\mathrm{d}_{\ell} \mathrm{A}_{\ell} \mathrm{L}_{\ell}\right) / \mathrm{A}_{\ell}}$
$=\left(\frac{\mathrm{d}_{\mathrm{u}} \mathrm{A}_{\mathrm{u}} \mathrm{L}_{\mathrm{u}}}{\mathrm{d}_{\ell} \mathrm{A}_{\ell} \mathrm{L}_{\ell}}+1\right) \frac{\mathrm{A}_{\ell}}{\mathrm{A}_{\mathrm{u}}}=\frac{5}{6}$