题目内容：

Ann had $100.She used part of her money to buy 7 ceramic cats,in which 3 of them are more expensive than the rest by $3.If she had $7 left,how much do the two types of ceramic cat cost?

优质解答

意思是说Ann有100元（美元当人民币了）,买7只陶瓷猫,其中3只比另外4只贵3元.她买完后还有7元,问2中猫的价格.
设便宜的猫X元,贵的猫X+3元.3（X+3）+4X=93,所以X=12,
所以便宜的猫12元,贵的猫15元.