Question

In a multiple choice question, there are four alternative answers, of which one or more are correct.A candidate decides to tick the answers at random. If he is allowed up to 3 chances to answer the question, the probability that he will get marks in the question is

• A. $\frac{1}{15}$
• B. $\frac{621}{3375}$
• C. $\frac{1}{5}$
• D. $\frac{4}{15}$

Answer 1

Answer: (C)

$\frac{1}{5}$

The total possible answers, he can give $=C(4,1)+C(4,2)+C(4,3)+C(4,4)=15$
and among them only one is correct and he can give three attempts.
The required probability (getting correct) $=\frac{3}{15}=\frac{1}{5}$