Three machinesE1, E2 and E3 in a
certain factory producing electric bulbs, produce 50%, 25% and 25%
respectively, of the total daily output of electric bulbs. It is known that
4% of the bulbs produced by each of machines E1 and E2 are
defective and that 5% of those produced by machine E3are
defective. If one bulb is picked up at random from a day’s
production, calculate the probability that it is
defective.