Explanation

Here, Mass of a body, $M = 5.00 \pm 0.05\ kg$ Volume of a body, $V = 1.00 \pm 0.05m^{3}$ Density, $\rho = \frac{M}{V}$ Relative error in density is $\frac{\mathrm{\Delta}\rho}{\rho} = \frac{\mathrm{\Delta}M}{M} + \frac{\mathrm{\Delta}V}{V}$ Percentage error in density is $\frac{\mathrm{\Delta}\rho}{\rho} \times 100 = \frac{\mathrm{\Delta}M}{M} \times 100 + \frac{\mathrm{\Delta}V}{V} \times 100$ $= \left( \frac{0.05}{5} \times 100 \right) + \left( \frac{0.05}{1} \times 100 \right) = 1\% + 5\% = 6\%$