Question

Albert is a math student who gets 80% of multiple choice questions correct. Assume each question is independent of the others. If Albert answers six multiple choice questions, what is the probability that he misses at least one question?

Group of answer choices
.90
.73
.32
.077
.24

Answer 1

The probability of missing atleast 1 question is 0.73

Using the binomial probability concept:

• 
  `nCx * p^(x) * (1-p)^(n-x)`
• n = number of questions = 6
• p = probability of failing = 1 - 0.8 = 0.2

P(misses atleast 1) = P(X = 1) + ... + P(X = 6)

Using the relation for each probability outcome:

P(X >= 1) =
`6C1 * 0.2^(1) * (0.8)^(5)`

P(X >= 1) = 0.7379

Hence, the probability of missing atleast 1 question is 0.73