PLEASE HELP!

If Sean's dad paid $41.40 on a meal that cost $36, what percent tip did he pay?

A) 12%
B) 15%
C) 18%
D) 20%

What is the definition of exponential decay?

Atriangle with all sides of equal length is a/an triangle. a. right b. scalene c. equilateral d. isosceles

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?