asap please!!

1 point Three jobs are executing in parallel. The processing time of each job has an exponential distribution with parameter 1 , and the processing times are independent. What is the expected time until the last job finishes? Type your answer... 1 point The time between successive requests to a server are independent random variables, each exponentially distributed with mean 2 (so parameter 1/2 ). Let Tn denote the time of the nth request. What are the mean and variance of Tn ? 2,nn,n22n,4n2n,4n2 None of the other choices