Which of the following compounds is soluble in benzene but almost insoluble in water?

Verdigris is

If $\frac{(1+i) x-i}{2+i}+\frac{(1+2 i) y+i}{2-i}=1$,then $(x, y)$ is equal to

If $A$ and $B$ are any two events,then $P(A \cup B) = $

In a biprism experiment,if the $5^{\text{th}}$ bright band with wavelength $\lambda_{1}$ coincides with the $6^{\text{th}}$ dark band with wavelength $\lambda_{2}$,then the ratio $\left(\frac{\lambda_{2}}{\lambda_{1}}\right)$ is:

In Young's double slit experiment,the $y$-coordinates of the central maximum and the $10^{th}$ maximum are $2\, cm$ and $5\, cm$ respectively. When the $YDSE$ apparatus is immersed in a liquid of refractive index $\mu = 1.5$,what will be the new $y$-coordinates?