LZ, your html codes are terrible! In a corporation, 50 percent of the male employees and 40 percent of the female employees are at least 35 years old.If 42 percent of all the employees are at least 35 years old, what fraction of the employees in the corporation are females? A.3/5 B.2/3 C.3/4 D.4/5 E.5/6 category: M F number m f >35 0.5m 0.4f then (0.5m + 0.4 f) = 0.42 * (m + f) so m = 0.25 f so percentage of female = f / (m + f) = 1 / 1.25 = 4/5 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 category Sat Sun Mon risk of rain 0.2 0.2 0.2 risk of no rain 0.8 0.8 0.8 If this guy comes back on Mon, then both Sat and Sun have no rain. So the probability for his returning on Monday = 0.8 * 0.8 * 0.2 =0.128 -- by 会员 sdcar2010 (2010/12/12 21:24:12)
sorry for the inconvernience that caused.I have tried several times to revise it.
Thank you so much for your feedback*_* | 
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发表于 2010-12-12 13:19:50
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