d
(d) Density, \(\rho = \frac{M}{V} = \frac{M}{{\pi {r^2}L}}\)

\( \Rightarrow \frac{{\Delta \rho }}{\rho } = \frac{{\Delta M}}{M} + 2\frac{{\Delta r}}{r} + \frac{{\Delta L}}{L}\)

\( = \frac{{0.003}}{{0.3}} + 2 \times \frac{{0.005}}{{0.5}} + \frac{{0.06}}{6}\)

\( = 0.01 + 0.02 + 0.01 = 0.04\)

\(\therefore \) Percentage error \( = \frac{{\Delta \rho }}{\rho } \times 100 = 0.04 \times 100 = 4\% \)