加拿大10年级数学题一道数学题..怎么也想不出来了A census taker came to a house with no one home.He asked a neighbour the ages of the three inhabitants and was told "the product of their ages is 252,the sum of their ages is the house number." Later,the census taker returned saying" I need more information." The reply was "the twins are named Derek and Doreen",the census wrote down the ages and left.What are their ages?
问题描述：
加拿大10年级数学题
一道数学题..怎么也想不出来了
A census taker came to a house with no one home.He asked a neighbour the ages of the three inhabitants and was told "the product of their ages is 252,the sum of their ages is the house number." Later,the census taker returned saying" I need more information." The reply was "the twins are named Derek and Doreen",the census wrote down the ages and left.
What are their ages?
答
三个住户，x x y（因为有两人是一对双胞胎，所以设两个x）
三人年龄乘积是252，所以xxy=252
三人年龄和是房子的号码？但这个条件没有给出来。
所以这道题目没法解，缺少条件，房号
答
三个人的年龄之积为252，其中两人是双胞胎，所以年龄相等。
由题意，设双胞胎的年龄为x，另一人的年龄为y，
得252＝(x^2)y
可能的情况是x=1,y=252或x=2,y=63或x=3,y=28或x＝6，y＝7
答
孩子3岁
父亲或母亲28岁
还有2,2,63的可能