Zero error of an instrument introduces

What is the fractional error in $g$ calculated from $T = 2\pi \sqrt {l/g} $ ? Given fraction errors in $T$ and $l$ are $ \pm x$ and $ \pm y$ respectively?

The length of a cylinder is measured with a meter rod having least count $0.1\, cm$. Its diameter is measured with vernier calipers having least count $0.01\, cm$. Given that length is $5.0 \,cm$. and radius is $2.0 \,cm$. The percentage error in the calculated value of the volume will be ……… $\%$

The length of a uniform rod is $100.0 \,cm$ and radius is $1.00 \,cm$. If length is measured with a meter rod having least count $1 \,mm$ and radius is measured with vernier callipers having least count $0.1 \,mm$, the percentage error in calculated volume of cylinder is …………. $\%$

A physical quantity $X$ is related to four measurable quantities $a,\, b,\, c$ and $d$ as follows $X = a^2b^3c^{\frac {5}{2}}d^{-2}$. The percentange error in the measurement of $a,\, b,\, c$ and $d$ are $1\,\%$, $2\,\%$, $3\,\%$ and $4\,\%$ respectively. What is the percentage error in quantity $X$ ? If the value of $X$ calculated on the basis of the above relation is $2.763$, to what value should you round off the result.