问一道GWD数学 GWD8-Q6

chenping0123

Q6:
If two copying machines work simultaneously at their respective constant rates, how many copies do they produce in 5 minutes?
(1)    One of the machines produces copies at the constant rate of 250 copies per minute.
(2)    One of the machines produces copies at twice the constant rate of the other machine.
    
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

很简单的一道题，我选C，答案选E。不知道为什么，请教NN

ssierra

兩個條件單獨肯定都不充分

兩個條件一起的話，只知道一臺機器的速度是每分鐘250，有一臺的速度是另一臺的2倍，但是幷不知道誰是誰的2倍，也即是說另一臺可能是500也可能是125，故也不充分。選E

chenping0123

谢谢啊！

再帮我看一下：
Q22:
At a garage sale, all of the prices of the items sold were different.  If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?

A.    33
B.    34
C.    35
D.    36
E.    37

这题不是选B吗？答案是E

sheikh239

答案错了

ssierra

Q22應該是答案錯吧。。。