Following observations were taken with a vernier callipers while measuring the length of a cylinder

$3.29 \,cm, 3.28\, cm, 3.29 \,cm, 3.31 \,cm,$ $ 3.28\, cm, 3.27 \,cm, 3.29 \,cm, 3.30\, cm$

Then find Absolute error in forth and eighth observation

The length, breadth and thickness of a strip are $(10.0 \pm 0.1)\; cm ,(1.00 \pm 0.01) \;cm$ and $(0.100 \pm 0.001)\; cm$ respectively. The most probable error in its volume will be?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$

Assertion $A$ : A spherical body of radius $(5 \pm 0.1)$ $mm$ having a particular density is falling through a liquid of constant density. The percentage error in the calculation of its terminal velocity is $4\,\%$.

Reason $R$ : The terminal velocity of the spherical body falling through the liquid is inversely proportional to its radius.

In the light of the above statements, choose the correct answer from the options given below on :

What is error in measurement ? What is mistake in measurement ?

$Assertion$ : The error in the measurement of radius of the sphere is $0.3\%$. The permissible error in its surface area is $0.6\%$

$Reason$ : The permissible error is calculated by the formula $\frac{{\Delta A}}{A} = \frac{{4\Delta r}}{r}$

An experiment measures quantities $a, b$ and $c$, and quantity $X$ is calculated from $X=a b^{2} / c^{3}$. If the percentage error in $a$, $b$ and $c$ are $\pm 1 \%, \pm 3 \%$ and $\pm 2 \%$, respectively, then the percentage error in $X$ will be