An organic compound $\mathrm{X}$ with molecular formula ${\mathrm{C}}_{11}{\mathrm{H}}_{14}$ gives an optically active compound on hydrogenation. Upon ozonolysis, $\mathrm{X}$ produces a mixture of compounds $-\mathrm{P}$ and $\mathrm{Q}.$ Compound $\mathrm{P}$ gives a yellow precipitate when treated with ${\mathrm{I}}_2$ and $\mathrm{NaOH}$ but does not reduce Tollen's reagent. Compound $\mathrm{Q}$ does not give any yellow precipitate with ${\mathrm{I}}_2$ and $\mathrm{NaOH}$ but gives Fehling's test. The compound $\mathrm{X}$ is: