here's were the 4 signals for xylene come from.
we'll number the carbons to make it easier. C1 would be the carbon with methyl group attached to it and going clockwise.
C1 and C3, hydrogens on methyl are equivalent. results in singlet.
C2 would give rise to another singlet
C4 and C6 their hydrogens are equivalent. You get a doublet
lastly C5, you get a triplet.
Did this come from top score? I remember a question they had on xylene