Question

A fair coin is tossed 6 times. The variance of the number of heads is

• A. $3$
• B. $3/2$
• C. $3/4$
• D. $2$

Answer 1

Answer: (B)

$3/2$

$p=\frac{1}{2}$
Variance $=np(1-p)$

$=6\left(\frac{1}{2}\right)(1-\frac{1}{2})$

$=\frac{6}{4}$

$=\frac{3}{2}$