作者momber (25y还在十字路口)
看板GMAT
标题Re: [问题] GWD3 计量问题
时间Tue Mar 31 18:45:16 2009
※ 引述《wangyihui400 (wanda)》之铭言：
: 这是我这一回里不会的问题,有点多有5题,麻烦大家耐心帮我解一下,感激不尽!!
: GWD3
: 2
: On Saturday morning, Malachi will begin a camping vacation and he will return
: home at the end of the first day on which it rains. If on the first three
: days of the vacation the probability of rain on each day is 0.2, what is the
: probability that Malachi will return home at the end of the day on the
: following Monday?
: A. 0.008
: ﹡B. 0.128
: C. 0.488
: D. 0.512
: E. 0.640
P(礼拜六没下雨) * P(礼拜天没下雨) * P(礼拜一下雨) = 0.8*0.8*0.2=0.128
: Q7:
: If x < 0, then √(-x ‧∣x∣) is
: ﹡A. –x
: B. -1
: C. 1
: D. x
: E. √x
这种正负的题目直接代-1解最快
原题= √(-(-1) ‧∣-1∣) = √1 = 1 = -(-1) = -x
然後稍微想一下就知道答案不会是C.
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