The stock of a ware house consists of boxes of high, medium, or low quality lightbulbs in respective proportions 1:2:2. The probability of bulbs of three types being unsatisfactory are 0.0, 0.1,0.2 respectively. If a box is chosen at random and two bulbs in it are tested and found to be satisfactory, what is the probability that it contains bulbs (i) of high quality (ii) of medium quality (iii) of low quality?