An unbiased die is thrown 3 times. If getting a 2 or 5 is considered a success, find the probability of at least 2 successes.

Solution

Here n = 3
p = P(2 or 5) = $1 over 6 plus 1 over 6 space equals space 2 over 6 equals space space 1 third$
q = 1 - p = 1 - $1 third space equals 2 over 3$
P(at least two successes) = P(2) + P(3)
$equals space straight C presuperscript 3 subscript 2 space open parentheses 2 over 3 close parentheses space open parentheses 1 half close parentheses squared plus space straight C presuperscript 3 subscript 3 space open parentheses 1 half close parentheses cubed space equals 3 over 1 cross times 1 over 6 plus 1 cross times 1 over 8 space equals 1 half plus 1 over 8 space equals fraction numerator 4 plus 1 over denominator 8 end fraction space equals 5 over 8$

For Daily Free Study Material Join wiredfaculty

Probability

An unbiased die is thrown 3 times. If getting a 2 or 5 is considered a success, find the probability of at least 2 successes.

Some More Questions From Probability Chapter

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction