In a blue box are the numbers 3 and 5. In a red box are the numbers 4, 5 and 12. While in a green box are the numbers 5 and 13. Suppose we will assign values to x, y, and z by choosing their values from these boxes. The value of x will be chosen from the blue box. The value of y from the red box and the value of z from the green box. What is the probability that a isosceles triangle can be formed with sides of x, y, and z?