The execution time of a certain class of job in the Edison supercomputer is a continuous random variable X which is Uniformly distributed over (40, 80) seconds, i. e., X ⇠Unif(40,80). You run 50 jobs. a.)20pts What is the probability that the total execution time is 3000 seconds? b.)5pts what is the probability that a single job takes less than 50 seconds? c.)5pts what is the probability that a single job takes less than 35 seconds? d.)5pts what is the probability that a single job takes less than 120 seconds?