设每件商品售价为x元,则销售量为[200-10(x-50)]件, 由题意得:(x-40)[200-10(x-50)]=2000, 整理得:x 2 -110x+3000=0, 解得x 1 =60,x 2 =50. 当x=60时,销售量为:200-10(x-50)=200-10(60-50)=100(件); 当x=50时,销售量为:200件. 答:该商店销售了这种商品100或200件,每件售价为60或50元.