Skip to content
dronacharya.ai
← JEE Main 2021 · 24 Feb · Shift 1
MathematicsSingle correct+4 / -1Question 78 of 90

JEE Main 2021 · 24 Feb · Shift 1, Mathematics question 78

An ordinary dice is rolled for a certain number of times. If the probability of getting an odd number 2 times is equal to the probability of getting an even number 3 times, then the probability of getting an odd number for odd number of times is :

Choose one option
Answer and worked solution

Official answer: D

Number of rolls. (n2)=(n3)\binom n2=\binom n3 gives n=5n=5.

Odd count of odd results (51)+(53)+(55)32=1632=12\frac{\binom51+\binom53+\binom55}{32}=\frac{16}{32}=\frac12.

(D)

Topics:Binomial distribution
← Previous questionNext question →