$ \frac{{\Delta V}}{V}\,\, \times \,\,100\,\, = \,\,\frac{{\Delta \ell }}{\ell }\,\, \times \,\,100\,\, + \,\frac{{\Delta w}}{w}\,\, \times \,\,100\,\, + \;\,\frac{{\Delta t}}{t}\,\, \times \,\,100$

$ = \,\,\frac{{0.1}}{{10}}\,\, \times \,\,100\,\, + \;\,\frac{{0.01}}{1}\,\, \times \,\,100\,\, + \;\,\frac{{0.001}}{{0.1}}\,\, \times \,\,100$

$= \,\,\left( {0.01\,\, + \;\,0.01\,\, + \;\,0.01} \right)\% \,\, = \,\,0.03\% \;\,$