I need help for these 2 tasks:

1.Let’s suppose that the duration of faultless operationξof one computer is following an exponential distributionξ , whichbelongs toЕх (λ).You have to found the valuation of the parameterλ, if we have observations on the duration of faultless operation of 5 computers- 2,3,5,4 and 7 years. What is the expected dispersion of the duration of faultless operation?

2.Let’s suggest that a heavy earthquake is happening average once per 10 years. What is the probability in the next 30 years an earthquake to happen?