a) 10 correct
There are 20 questions with 4 options each.
Probability of guessing a right answer each time is ¼ = 0.25
So, probability of guessing 10 correct answers is P(X=10)
(
20
10
)
(
0.25
)
10
(
0.75
)
10
= 0.0099
b) Probability of guessing at least 5 correct is P(X
≥
5
¿
∑
k
=
5
20
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- Winter '16
- Archana Chauhan
- Binomial, Probability, right answer
