The quantity of a radioactive substance follows the law of uninhibited decay. If 124 grams are present to start and if 50 grams are present after 15 minutes, approximately how many grams will be present after 34 minutes?

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?