Question

In a bolt factory, machines A,B and C manufacture respectively 25%,35% and 40% of the total balls . Of their output 5, 4 and 2 percent are respectively defective bolts. A bolt is drawn at random from the product. If the bolt drawn is found to be defective, what is the probability that it is manufactured by the machine B.

• A. $\frac{27}{68}$
• B. $\frac{71}{345}$
• C. $\frac{28}{69}$
• D. $\frac{14}{69}$

Answer 1

The correct option is C $\frac{28}{69}$

Option C is the correct answer. Check the video for the approach.