Question

A die is tossed twice. Getting an odd number is termed a success. The probability distribution of number of successes (X) is formed. Then its mean, variance are

• A. $1,\frac{1}{2}$
• B. $\frac{1}{2},1$
• C. $\frac{1}{2},\frac{1}{2}$
• D. $1,1$

Answer 1

Answer: (A)

$1,\frac{1}{2}$

Here, $n=2,p=\frac{1}{2},q=1-p=\frac{1}{2}$
$\therefore$ mean $=np=1$ and variance $=npq=\frac{1}{2}$