Foundations of Math 12. Please show your work.

19. A company has two factories that manufacture light bulbs. Suppose that 55% of the light bulbs are manufactured in factory A and 45% come from factory B. In factory A 0.7% of the bulbs are defective and in factory B 0.3% of the bulbs are defective. Suppose a defective light bulb is discovered. What is the probability that the defective bulb came from factory B? 19. 4mm