According to Internet security experts, approximately 90% of all e-mail messages are spam (unsolicited commercial e-mail), while
the remaining 10% are legitimate. A system administrator wishes to see if the same percentages hold true for the e-mail traffic on her servers. She randomly selects e-mail messages and checks to see whether or not each one is legitimate. (Unless otherwise specified, round all probabilities below to four decimal places; i.e. your answer should look like 0.1234, not 0.1234444 or 12.34%.) Assuming that 90% of the messages on these servers are also spam, compute the probability that the first legitimate e-mail she finds is the fifth message she checks:
Superman was said to be "faster than a speeding bullet." A Winchester rifle bullet travels at a speed of 1,924 miles per hour (mph). Which of the equations, where T is the time in hours and D the distance in miles, describe a speed faster than the speed of a Winchester bullet?
