In: Statistics and Probability
A monkey randomly hits a keyboard with 26 letters, one per second.
(a) How long, in average, will it take for the monkey to type the letter Z for the first time?
I believe that each letter is random and independent, meaning that the probability of the monkey typing any letter is (1/26). Therefore, the expected value is equal to the sum from 1 to 26 times (1/26), yielding 13.5 seconds. I am unsure how to move forward with parts (b) and (c).
(b) How long, in average, will it take for the monkey to type the letter Z for the second time?
(c) How long, in average, will it take until the monkey types two Z’s in a row? (Hint: condition on the event that the Monkey types Z on the first second).