Hello tutors, can I please get you assistance with the following ? Thank You so much

A lot of iphones is to be inspected for defects by an engineer in a phone manufacturing plant. Suppose that, in a tray containing twenty phones, four are defective (D) and sixteen are working properly (W) so that the P(W)=16/20 and P(D)=4/20. Two phones are to be selected with replacement. After listing the sample space, find the probabilities of the following events:

(a) neither is defective;

(b) at least one of the two are defective.

*please display the steps, what is on the left hand side of the equal signs, the final answer*