∵甲數(shù)=40,乙數(shù)=30
∵甲數(shù)/乙數(shù)=40/30=4/3
∴甲數(shù)是乙數(shù)的3分之4
∵乙數(shù)/甲數(shù)=30/40=3/4
∴乙數(shù)是甲數(shù)的4分之3
（甲數(shù)-乙數(shù)）／乙數(shù)=（40-30）／30×100%=33.33%
∴甲數(shù)比乙數(shù)多33.33%
乙數(shù)-甲數(shù)=30-40=-10
乙數(shù)比甲數(shù)少10