Use the binomial distribution.

where n= total number of trials, p=probability of success which in this case is 0.85, x= number of successes

a. What is the probability that both pieces are defect free?

Use n=2, x=2, and p=0.85 in the above equation

b. What is the probability that neither piece is defect free?

Use n=2, x=0, and p=0.85 in the above equation

c. Suppose at least one of the pieces has a flaw. What is the probability that BOTH are defective?

find P(X=1)+P(X=2) using the same equation