If john ate 3 cheese burgers in in 30 minutes, how many would he eat in 1 hour if he kept the same pace.

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?

9/10 divide by -3/15 as a mixed number

Me. i can't figure out this question. give an explanation too. .