题目内容：

4 years ago,mary's age was 0.25 of her mother's.mary is now 15 years old.how old.how old is is her mother now

优质解答

意思是：4年前,玛丽的年龄为0.25岁的她母亲的.玛丽现在15岁.多大年纪.是她母亲多大了吗?设now mary's mother'sage is x
(x-4)/4=15-4
x=(15-4)*4+4=48