The chartered Financial analyst (CFA) is a designation earned after taking three annual exams (CFA I, II and III. The exams are taken in early June. Candidates who pass an exam are eligible to take the an exam for the next level. The pass rates for Levels I, II and III are 0.53, 0.7, and 0.8 respectively . Suppose that 3000 candidates take the level I exam, 2500 take the level II exam and 2000 take the Level III exam. A randomly selected candidate who took the CFA exam tells you that he hass passed the exam. Whta is the probability that he took the CFA I exam.