Question

An which contain 5 red and 2 black balls. Two balls are drawn at random. X denotes number of black balls drawn. What are possible values of X?

Answer 1

Answer:

I ask this question from my brother

Step-by-step explanation:

X is a random variable.

Step-by-step explanation:

Given : An urn contain 5 red and 2 black balls, two balls are randomly drawn without replacement. Let x represent number of black ball draw.

To find : What are the possible value of x?

Solution :

An urn contain 5 red and 2 black balls.

The number of ways in which two balls can be represented are

{(RR), (RB), (BR), (BB)}

Let X represent the number of black balls. Possible values of X are:

X(RR) = 0, X(RB) = 1, X(BR = 1) and X (BB) = 2.

Therefore the possible values of X are 0, 1 and 2.

P(X=0)=\frac{1}{4}P(X=0)=

4

1

P(X=1)=\frac{2}{4}P(X=1)=

4

2

P(X=2)=\frac{1}{4}P(X=2)=

4

1

\sum X_i=P(X=0)+P(X=1)+P(X=2)∑X

i

=P(X=0)+P(X=1)+P(X=2)

\sum X_i=\frac{1}{4}+\frac{2}{4}+\frac{1}{4}∑X

i

=

4

1

+

4

2

+

4

1

\sum X_i=\frac{4}{4}∑X

i

=

4

4

\sum X_i=1∑X

i

=1

Therefore, X is a random variable.