van der Waal's gas equation for $n$ number of moles is given by the formula $\left(P+\frac{n^{2}a}{V^2}\right)\left(V-nb\right)=nRT$, where $P$ is pressure, $V$ is volume, $R$ is gas constant and $T$ is temperature.

Dimensions of $b$ is

van der Waal's gas equation for $n$ number of moles is given by the formula $\left(P+\frac{n^{2}a}{V^2}\right)(V-nb)=nRT$, where $P$ is pressure, $V$ is volume, $R$ is gas constant and $T$ is temperature.

The dimensions of a rectangular block measured with an instrument having least count $0.1 \mathrm{mm}$ is $5.0 \mathrm{mm}\times 10.0 \mathrm{mm}\times 10.0 \mathrm{mm}.$ The maximum percentage error in the measurement of volume of the block is