Question

In an objective exam which has 3 answer options each for all the 20 questions, what is the probability that Samir answers 9 questions incorrectly?​

Answer 1

Answer:

Yes 18 is the answer bro

Step-by-step explanation:

Kindly Mark Me As Brainiest bro

Answer 2

Answer:

$\frac{11}{243}$

Step-by-step explanation:

Probability of correct guess = $p(c)=\frac{1}{3}$

Probability of wrong guess = $p(w)=\frac{2}{3}$

Probability that 4 answers are guessed correctly = $p(4)=^5C_{4} (\frac{1}{3} )^4 (\frac{2}{3} )$

Probability that 5 answers are guessed correctly = $p(5)=^5C_{5} (\frac{1}{3} )^5$

Thus, that the student solves 4 or more questions correctly just by guessing = $p(4)+p(5)=(\frac{10}{3} )^5+(\frac{1}{3} )^5=\frac{11}{243}$