Zero error of an instrument introduces

The percentage error in the measurement of $g$ is $.....\%$ (Given that $g = \frac{4 \pi^2 L}{T^2}$,$L = (10 \pm 0.1) \, cm$,$T = (100 \pm 1) \, s$)

$A$ physical quantity $p$ is described by the relation $p = a^{1/2} b^2 c^3 d^{-4}$. If the relative errors in the measurement of $a, b, c$ and $d$ are $2\%$,$1\%$,$3\%$ and $5\%$ respectively,then the relative error in $p$ will be ........... $\%$.

$Assertion$ : When percentage errors in the measurement of mass and velocity are $1\%$ and $2\%$ respectively,the percentage error in $K.E.$ is $5\%$.
$Reason$ : $\frac{{\Delta E}}{E} = \frac{{\Delta m}}{m} + \frac{{2\Delta v}}{v}$

When two resistors of resistances $R_1=(200 \pm 2) \Omega$ and $R_2=(400 \pm 4) \Omega$ are connected in series,then the equivalent resistance of the combination is

If $x = a - b$,then the percentage error in $x$ will be