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 days production, calculate the probability that it is defective.

Explanation

A = tube picked is defective.



`P(E_{1})=50 %=frac{50}{100}=frac{1}{2} `


`P(E_{2})=25 %_{0}=frac{25}{100}=frac{1}{4} `


`P(E_{3})=25 %_{0}=frac{25}{100}=frac{1}{4} `


`P(A | E_{1})=4 %=frac{4}{100}=frac{1}{25} `


`P(A | E_{2})=4 %=frac{4}{100}=frac{1}{25} `


`P(A | E_{3})=5 %=frac{5}{100}=frac{1}{20} `


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