Who knows how to do this problem

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?

Present age of man is 45 years, 5 years back his age was 4 times age of his son what is present age of his son?

Consider the sequence below. 3 , 1 , 1/3 , 1/9 , select the explicit function which defines the sequence.