Total number of structural isomers possible with the formula, C3H8O is ‘X’. Total number of simple ethers possible with the formula, C2H6O is ‘Y’. Sum of X and Y is

C3H8O : 1 CH3-CH2-CH2-OH 10 ; 2 CH3-CH(OH)-CH3 20 ; 3 CH3-CH2-O-CH3 (unsymmetrical or mixed ether) ; Stereo isomerism cannot be exhibited ; C2H6O : 1 CH3-CH2-OH 10 ; 2 CH3-O-CH3 (symmetrical or simple ether) ; Stereo isomerism cannot be exhibited ;