Question

In a bolt factory machines a, b and c manufacture respectively 25%, 35% and 40% of the total output; 5, 4 and 2 percent are defective bolts respectively. A bolt drawn at a random from the product and is found to be defective. What are the probabilities that it was manufactured from machines a, b and c?

Answer 1

Answer:

0.0345

Step-by-step explanation:

The probabilities are as follows :

1) P(defective and from a) :

5/100 × 25/100 = 1/80

2) P(defective and from b)

= 4/100 × 35/100 = 7/500

3) P(defective and from C) :

= 2/100 × 40/100 = 1/125

P(it is from a or b or c) = p(from a) + p(from b) + p(from c)

1/80 + 7/500 + 1/125 = 69/2000

= 0.0345

Answer 2

Answer:

0.0345

Step-by-step explanation:

The probabilities are as follows :

1) P(defective and from a) :

5/100 × 25/100 = 1/80

2) P(defective and from b)

= 4/100 × 35/100 = 7/500

3) P(defective and from C) :

= 2/100 × 40/100 = 1/125

P(it is from a or b or c) = p(from a) + p(from b) + p(from c)

1/80 + 7/500 + 1/125 = 69/2000

= 0.0345