The original price of a pair of headphones is $39.99 before tax. When David bought the headphones they rang up for $31.99 before tax. He then paid 6% sales tax on the discounted price. Part A: What is the percent discount on the headphones? Show all work and steps in your solution. (5 points)
Part B: What is the total amount that Dalton paid for the headphones including tax? Show all work and steps in your solution. (5 points)

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?