If $A$ and $B$ are two physical quantities having different dimensions,then which of the following cannot denote a physical quantity?

In the expression $A=B+\frac{C}{D+E}$,the dimensions of physical quantities $B$ and $C$ are $[L^{1} M^{0} T^{-1}]$ and $[L^{1} M^{0} T^{0}]$ respectively. The dimensions of quantities $A, D$ and $E$ are

The volume of a liquid flowing out per second of a pipe of length $l$ and radius $r$ is written by a student as $V = \frac{\pi p r^4}{8 \eta l}$,where $p$ is the pressure difference between the two ends of the pipe and $\eta$ is the coefficient of viscosity of the liquid having the dimensional formula $[M^1 L^{-1} T^{-1}]$. Check whether the equation is dimensionally correct.

$A$ and $B$ possess unequal dimensional formulas. Then,which of the following operations is not possible in any case?

If the buoyant force $F$ acting on an object depends on its volume $V$ immersed in a liquid,the density $\rho$ of the liquid,and the acceleration due to gravity $g$,then the correct expression for $F$ can be:

$A$ physical quantity $X$ is given by $X = \frac{2 k^3 l^2}{m \sqrt{n}}$. The percentage errors in the measurements of $k, l, m,$ and $n$ are $1 \%, 2 \%, 3 \%,$ and $4 \%$ respectively. The percentage uncertainty in the value of $X$ is: (in $\%$)