Mary saved exactly 60 percent of the total allowance she received in the last two weeks,and spent

题目

Mary saved exactly 60 percent of the total allowance she received in the last two weeks,and spent
the rest.If she received $20 for allowance each week and spent $12 of her first week's allowance,which of the following must be true?

答案

玛丽节省下了之前两周收到的津贴总额的60％,花掉了其余的部分.如果她每周得到的津贴为20美元,而她花去了上周津贴中的12美元,那么以下哪项必定为真?