Answer:
The probability that a randomly selected automobile manufactured by the company will have a defective microprocessor is 6.2 %.
Step-by-step explanation:
Given:
The probability of getting a microprocessor from firm A is, 
The probability of getting a microprocessor from firm B is, 
The probability of getting a microprocessor from firm C is, 
Now, let event D be having a defective microprocessor at random.
So, as per the question,
Probability of producing a defective microprocessor from firm A is, 
Probability of producing a defective microprocessor from firm B is, 
Probability of producing a defective microprocessor from firm C is, 
Now, probability of having a defective microprocessor when selected at random is given as:

Therefore, the probability that a randomly selected automobile manufactured by the company will have a defective microprocessor is 6.2 %.