Question

A short quiz was to be held at Meenakshi's school. As an unprepared student, she planned to randomly guess all the answers on the twelve true or false questions. What is the probability that at least 2 of Meenakshi's answers will be correct?

Answer 1

0.9968

Explanation:

Given that:

P of being correct = 0.5 (since there are only 2 options in each question with only one bring correct).

1 - p = 1 - 0.5 = 0.5

Number of questions, n = 12

Probability that atleast 2 questions are correct

P(x ≥ 2) = p(x = 2) + p(x = 3) +... + p(x = 12)

P(x =x) = nCx * p^x * (1 - p)^(n - x)

The sun of the individual probabilities gives us the answer or we could use the binomial probability calculator :

Hence,

P(x ≥ 2) = 0.9968