7 A grocery store s sponsoring a sales promotion where the c

(7) A grocery store s sponsoring a sales promotion where the cashiers give away one of the letters: A, E, L,S, U, V for each purchase. If the customer collects all six (spelling VALUES), he or she gets $20.00 worth of groceries free. What is the expected number of trips to a store a customer needs to make?

Solution

Prob of getting each letter is 1/6

No of letters = 6.

Each time only 1 letter is given for each purchase.

Expected no of trips minimum =6 if he gets each time one letter

maximum = atleast one letter getting = infinity.