Harry consumes caffeinated beverages at an average rate of 3

Harry consumes caffeinated beverages at an average rate of 3 per day.

(a) find the probability that the time between two caffeinated beverages is greater that 9 hours. derive the formulation using c.d.f., but do not calculate it.

(b) calculate the expected time until Harry consumes caffeinated beverages.

(c) find the probability that the time until Harry consumes 10 caffeinated beverages is less than 4 days.

Solution