一道英语智力题,求大神级解答!急!
TomandMaryarebrotherandsister.Whenpeopleaskedhowmanysiblings(兄弟姐妹)therhad,Tomsaid,"Ihavetwiceasmanysisterasbrothers."However,Marysaid,"Ihaveanequalnumberofbrothersandsisters."Howmanybrothersandsistersdotheyhave?