Six people, named W, X, Y, Z, T and U, each are of different ages. The age of W is 30. The age of U is one-fourth the age of T. The age of Y is two times the age of X. The age of T is five times the age of Y. The age of W is two times the age of U. If the age of X is one-fourth the age of Z, what is the age of Z?