As an incentive to get new customers, the local branch of a bank launched 'bouncing for bucks.'

Question:

As an incentive to get new customers, the local branch of a bank launched 'bouncing for bucks.' During this week long event, an customer opening a new checking account with the bank would have the opportunity to throw a bouncy rubber ball into a large box divided into squares. Each square was labeled with a dollar amount that would be deposited into his/her checking account. The way the box was labeled is shown below. What is the probability that three customers in a row do not get $50?