A trisubstituted compound '$$\mathrm{A}$$', $$\mathrm{C}_{10} \mathrm{H}_{12} \mathrm{O}_{2}$$ gives neutral $$\mathrm{FeCl}_{3}$$ test positive. Treatment of compound 'A' with $$\mathrm{NaOH}$$ and $$\mathrm{CH}_{3} \mathrm{Br}$$ gives $$\mathrm{C}_{11} \mathrm{H}_{14} \mathrm{O}_{2}$$, with hydroiodic acid gives methyl iodide and with hot conc. $$\mathrm{NaOH}$$ gives a compound $$\mathrm{B}, \mathrm{C}_{10} \mathrm{H}_{12} \mathrm{O}_{2}$$. Compound 'A' also decolorises alkaline $$\mathrm{KMnO}_{4}$$. The number of $$\pi$$ bond/s present in the compound '$$\mathrm{A}$$' is _____________.

Number of compounds giving (i) red colouration with ceric ammonium nitrate and also (ii) positive iodoform test from the following is ___________

The number of stereoisomers formed in a reaction of $$(±)\mathrm{Ph}(\mathrm{C}=\mathrm{O}) \mathrm{C}(\mathrm{OH})(\mathrm{CN}) \mathrm{Ph}$$ with $$\mathrm{HCN}$$ is ___________.

$$\left[\right.$$where $$\mathrm{Ph}$$ is $$-\mathrm{C}_{6} \mathrm{H}_{5}$$]

The spin only magnetic moment of the complex present in Fehling's reagent is __________ B.M. (Nearest integer).