Count faults across two boxes rather than test each box separately

The probability that a particular make of light bulb is faulty is 0.2. The light bulbs are packed in boxes of 12.

(a) Find the probability that in a certain box, there are

(i) no faulty light bulbs

(ii) more than 3 faulty light bulbs

(b) A buyer accepts a consignment of 50 boxes, if, when he chooses two boxes at random, he finds that they contain no more than one faulty light bulb altogether. Find the probability that he will accept the consignment.