Question

The probability of guessing the correct answer to a certain test is $\frac{x}{2}$. If the probability of not guessing the correct answer to this questions is $\frac{2}{3}$, then $x$ is equal to ______________.

• A. $\frac{2}{3}$
• B. $\frac{3}{5}$
• C. $\frac{1}{3}$
• D. $\frac{1}{2}$

Answer 1

Answer: (A)

$\frac{2}{3}$

Probability of guessing the correct answer $=\frac{x}{2}$

Probability of guessing the incorrect answer $=1-\frac{x}{2}=\frac{2}{3}$

$\therefore \frac{x}{2}=\frac{1}{3}$ or $x=\frac{2}{3}$