A manufacturer of VCRs plans to purchase a particular component from suppliers A, B and C. 30% of the components are to be purchased from A, 20% from B and 50% from C. In the past, 3% of components purchased from A have been defective, 5% of those purchased from B have been defective and 4% of those purchased from C have been defective. Upon arrival, the components are thrown into a box with no identifiers as to manufacturer. A component is randomly selected and it turns out to be defective. What is the probability that is was manufactured by supplier B?