Problem Solving
试题详情
题目：
The function f is defined for each positive three-digit integer n by f ( n ) = 2x 3y 5z, where x , y and z are the hundreds, tens, and units digits of n , respectively. If m and v are three-digit positive integers such that f ( m ) = 9 f ( v ), then m - v =
选项:
A、8
B、9
C、18
D、20
E、80
答案:
D
