Answer:
The probability is 0.28157
Step-by-step explanation:
The number of answers are 40 answers ( 10 questions and 4 answer each)
The number of correct answers is only 10
So the probability that he answers 2 exactly out of 10 means he correctly selected 2 answers
The probability will be;
10 C 2/ 40 C 10
This mean out of the total 10 correct, he selects 2 and out of the total 40 , he selects 10
The probability of selecting a correct answer is;
1/4 while the probability of selecting a wrong one is 3/4
So probability of selecting 2 correct out of a total 10 will be
10 C 2 (1/4)^2 (3/4)^8
= 0.28157
