Question

Three machines E₁,E₂,E₃ in a certain factory produce 50%, 25% and 25%, respectively, of the total daily output of electric tubes. It is known that 4% of the tubes produced one each of machines E₁ and E₂ are defective, and that 5% of those produced on E₃ are defective. If one tube is picked up at random from a day’s production, calculate the probability that it is defective.

Answer 1

Let A1 : Event that the bulb is produced by machine E1 A2 : Event that the bulb is produced by machine E2 A3 : Event that the bulb is produced by machine E3 A : Event that the picked up bulb is defective Here, P(A1) = 50% = 50/100 = 1/2, .'. The probability that the picked bulb is defective,0.0425