State the rule for the error in the result due to multiplication and division of two physical quantities.

(N/A) When two physical quantities $A$ and $B$ are multiplied or divided to obtain a result $Z$ (where $Z = AB$ or $Z = A/B$),the relative error in the result $Z$ is equal to the sum of the relative errors in the individual quantities $A$ and $B$.
Mathematically,if $Z = AB$ or $Z = A/B$,then the maximum fractional error or relative error is given by:
$\frac{\Delta Z}{Z} = \frac{\Delta A}{A} + \frac{\Delta B}{B}$
Here,$\Delta A$ and $\Delta B$ are the absolute errors in $A$ and $B$ respectively,and $\Delta Z$ is the absolute error in the result $Z$.