A company uses a ‘selling aptitude test’ in the selection of salesmen. Past experience has shown that only 70 per cent of all persons applying for a sales position achieved a classification ‘dissatisfactory’ in actual selling, whereas the remainder were classified as ‘satisfactory’, 85 per cent had scored a passing grade in the aptitude test.

Only 25 per cent of those classified dissatisfactory had passed the test on the basis of this information. What is the probability that a candidate would be a satisfactory salesman given that he passed the aptitude test?