Question

In six throws of a die, getting $4$ or $5$ is considered a success. The mean number of successes is

• A. $4$
• B. $3$
• C. $2$
• D. $1$

Answer 1

Answer: (C)

$2$

Mean number of success = $\mu =np$ where $n$ $=$ total number of trials $p$ $=$ probability of success
$n=6$ For getting $4$ or $5$ is considered a success, probability of success $=$ $\frac{2}{6}$
Mean number of success $=$ $\frac{2}{6}\times 6=2$