Number of isomeric compounds with molecular formula C_9 H_10 O which (i) do not dissolve in NaOH (ii) do not dissolve in HCl. (iii) do not give…

Number of isomeric compounds with molecular formula $\displaystyle \mathrm{C}_9 \mathrm{H}_{10} \mathrm{O}$ which (i) do not dissolve in NaOH (ii) do not dissolve in HCl . (iii) do not give orange precipitate with $\displaystyle 2,4$-DNP (iv) on hydrogenation give identical compound with molecular formula $\displaystyle \mathrm{C}_9 \mathrm{H}_{12} \mathrm{O}$ is $\displaystyle \_\_\_\_$.