How many strings of seven hexadecimal digits do not have any repeated digits? (b) How many strings of seven hexadecimal digits have at least one repeated digit? (c) What is the probability that a randomly chosen string of seven hexadecimal digits has at least one repeated digit? (Round your answer to the nearest tenth of a percent.) %

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?

Which system of linear inequalities is represented by the graph?

What is the length of the segment, endpoints of which are intersections of parabolas y=x2? 11 4 x? 7 4 and y=? 7 8 x2+x+ 31 8 ?