Two cores in a CPU serve jobs from a single queue. The time it takes one core to serve a randomly selected job is distributed as Expo(1/5), so that its average service time is 5 minutes. The other, more powerful core's service times are distributed as Expo(1/4), averaging 4 minutes. Cores work independently. Both cores are busy, and a new job arrives in the queue. What is the probability it will take longer than 5 minutes before the new job starts to be served?