[SOLVED] Probability(defective)

Question:

A computer accessories distributor obtains its supply of diskettes from manufacturers A and B, with 60% of the diskettes from manufacture A. The diskettes are packed by the manufacturers in packets of tens. The probability that a diskette produced by manufacturer A is defective is 0.05 whereas the probability that a diskette produced by manufacturer B is defective is 0.02.

Find the probability that a randomly chosen packet contains exactly one defective diskette.