Total number of cyclic stereo isomers possible with the formula, C5H10 is ‘X’. Total number of five membered ring compounds (structural only) possible with the formula, C5H10 is ‘Y’. Difference between X and Y is

Number of structurally isomeric cycloalkanes = 5 ;Number of structurally isomeric cyclic compounds= 5 ;Number of cyclic stereo isomers = 3 ;cis 1,2-dimethyl cyclo propane (meso) and trans 1,2-dimethyl cyclo propane (d and l);Total number of cyclic isomers = 7 ;