Given below is the frequency distribution table regarding the concentration of sulphur dioxide in the air in parts per million of a certain city for 30 days. Concentration 0.00-0.04 0.04-0.08 0.08-0.12 0.12-0.16 0.16-0.20 0.20-0.24 No. of days: 4 8 9 2 4 3 Find the probability of concentration of sulphur dioxide in the interval 0.12-0.16 on any of these days.