The maximum number of possible isomers (including stereoisomers) which may be formed on mono-bromination of 1-methylcyclohex-1-ene using Br₂ and UV light is ___________.

In the reaction given below, the total number of atoms having sp² hybridization in the major product P is _________.

The total number of possible isomers for [Pt(NH₃)₄Cl₂]Br₂ is ______.

Consider a triangle $$\Delta$$ whose two sides lie on the x-axis and the line x + y + 1 = 0. If the orthocenter of $$\Delta$$ is (1, 1), then the equation of the circle passing through the vertices of the triangle $$\Delta$$ is