A box contains 15 green and 10 yellow balls. If 10 balls… — JEE Main 2017 Mathematics PYQ

JEE Main 2017

A box contains 15 green and 10 yellow balls. If 10 balls are randomly drawn one-by-one with replacement, then the variance of the number of green balls drawn is

A.
$\frac{12}{5}$
B.
6
C.
4
D.
$\frac{6}{25}$

Show answer and solution

Correct option: A

Solution

This is a binomial distribution with n = 10, p = 15/25 = 3/5, q = 2/5.

Variance = npq = 10 × (3/5) × (2/5) = 60/25 = 12/5.

[JEE Main 2017]

Practise Probability the way it is asked

A timed set of real JEE Main Probability questions, graded as the exam grades. No sign-up.

Start a Probability test

More: all JEE Main Probability questions · JEE Main 2017 · Mathematics chapter list

JEE Main 2017 Mathematics question on Probability