Help with a, b, & c?

1-for what value of x is line a parallel to line b 2-for what value of x is line a parallel to line b

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?

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers