Question

Three machines A, B and C produce respectively 50%, 30% and 20% of the total number of items of a factory. The percentage of defective output of these machines are 3%, 4% and 5% respectively. if an item selected at random, find the probability that the item is non-defective.

Answer 1

Probability that the part is defective: $0.5*0.03+0.3*0.04+0.2*0.05=0.37.$

Probability that the part is non-defective: $1-0.37=0.63.$