Aldehydes Ketones And Carboxylic Acids

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 _____________.