c
${T}=\frac{2 {m}_{1} {m}_{2} {g}}{{m}_{1}+{m}_{2}}=\frac{2 \times 3 \times 5 \times 10}{8}$
$=\frac{75}{2}$
Stress $=\frac{{T}}{{A}}$
$\frac{24}{\pi} \times 10^{2}=\frac{75}{2 \times \pi {R}^{2}}$
${R}^{2}=\frac{75}{2 \times 24 \times 100}=\frac{3}{8 \times 24}$
$\Rightarrow {R}=0.125\, {m}$
${R}=12.5\, {cm}$
