扫描二维码，直接登录
题库 / Prep2007E2-DS-156
Each of the numbers w, x, y, and z is equal to either 0 or 1. What is the value of w + x + y + z ?
(1) ~$\frac{w}{2}+\frac{x}{4}+\frac{y}{8}+\frac{z}{16}=\frac{11}{16}$~
(2) ~$\frac{w}{3}+\frac{x}{9}+\frac{y}{27}+\frac{z}{81}=\frac{31}{81}$~
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
还没有题目讲解（毕出老师会陆续发布对官方考题的解读，请保持关注）。
此题错选C，看来如果只有0或1，那就把其中0或1其中一个分两次带入wxyz任何一个，就知道是否需要另一个等式了。又被骗了。
登录 或 注册 后可以参加讨论