Let x, y, z be three different positive integers each less than 20. What is the smallest possible value of expression _老师，og这道题我理解，有这样一道DS题希望老师解答解题思路和解题方法，我不知道怎样入手这道题： If xyz is a 3-digit integer and it is the product of two positive integers n and 9, then is x + y + z = 9? （1）x + y + z < 15 （2）x + y + z > 8 Answer: A出国考试答疑器_GMAT

Let x, y, z be three different positive integers each less than 20. What is the smallest possible value of expression