I'm using the exponential distribution to calculate a probability of an event to occur. $\lambda = 0.007$ failures/year. I am to calculate an expected time between 2 failures.
My approach was to calculate the probability of 1 failure to occur within a year and then somehow use the memorylessness property of exponential distributions. However, I'm absolutely stuck now since I don't understand how to get time out of this probability. Is there some specific formula I should turn to ? Any hints are welcome!