Here, Mass of a body, M = 5.00 ± 0.05 kg

Volume of a body, V = 1.00 ± 0.05 m³ 

Density,

$$\begin{gathered} \rho =\frac{M}{V} \\ \mathrm{Relative} \mathrm{error} \mathrm{in} \mathrm{density} \mathrm{is},\frac{∆\mathrm{\rho }}{\mathrm{\rho }}=\frac{∆\mathrm{M}}{\mathrm{M}}+\frac{∆\mathrm{V}}{\mathrm{V}} \\ \mathrm{Percentage} \mathrm{error} \mathrm{in} \mathrm{density} \mathrm{is} \\ \frac{∆\mathrm{\rho }}{\mathrm{\rho }}\times 100=\frac{∆\mathrm{M}}{\mathrm{M}}\times 100+\frac{∆\mathrm{V}}{\mathrm{V}}\times 100 \\ =\left(\frac{0.05}{5}\right)\times 100+\left(\frac{0.05}{1}\right)\times 100=1\%+5\%=6\% \end{gathered}$$