Probability of defective transistor = 5/15 = 1/3 and probability of non-defective transistor = 1−1/3 = 2/3 Probability that the inspector find a non-defective transistor = 2/3 × 2/3 × 2/3 = 8/27 Hence, probability that atleast one of d the inspectors find a defective transistors =1 − 8/27 = 19/27