An airline company serves, among several possible routes, a route to Frankfurt. However, it makes a stop: either via Amsterdam or Madrid. Out of all the customers the percentage that go to Madrid is 11% and the percentage that go to Amsterdam is 7%. If the probability that a customer that goes to Madrid continues to Frankfurt is is 0.2; and the probability that a customer that goes to Amsterdam continues to Frankfurt is 0.35, find the probability that a customer goes to Frankfurt.