Acidified potassium permanganate solution oxidises oxalic acid. The spin-only magnetic moment of the manganese product formed from the above reaction is ____________ B.M. (Nearest integer)

Two elements A and B which form 0.15 moles of A₂B and AB₃ type compounds. If both A₂B and AB₃ weigh equally, then the atomic weight of A is _____________ times of atomic weight of B.

Total number of possible stereoisomers of dimethyl cyclopentane is ____________.

The area of the polygon, whose vertices are the non-real roots of the equation $$\overline z = i{z^2}$$ is :