18. A diner has 20 desserts: 7 are slices of pie, 5 are pieces of cake, 8 are bowls of pudding. Jacobi wants to select two to eat. The rst dessert will be selected at random. and then the second will be chosen from the remaining dessert. What is the probability that the two desserts select are slices of pie? Do not round your intermediate computations. Round your nal answer to three decimal places