Question

The probability of guessing the correct answer to a question is $\frac{x}{2}$. If the probability of not guessing the correct answer to this question is $\frac{2}{3}$, then $x$ $=$ ___________.

• A. $2$
• B. $3$
• C. $\frac{2}{3}$
• D. $\frac{1}{3}$

Answer 1

Answer: (C)

$\frac{2}{3}$

We know that of the probability of either guessing the correct answer or not getting the correct answer is $1$.

The probability to answer correct answer is $\frac{x}{2}$.

So, $1=\frac{x}{2}+\frac{2}{3}$

$\Rightarrow \frac{x}{2}=\frac{1}{3}$

$\Rightarrow x=\frac{2}{3}$