The probability of guessing the correct answer to a certain question is `x`. If probability of not guessing the correct answer is `2/3`, then find x.

Options

A. `1//3`
B. `4//3`
C. `2//3`
D. None of these

Answer

To solve the problem, we need to find the value of \( x \), which represents the probability of guessing the correct answer. We are given that the probability of not guessing the correct answer is \( \frac{2}{3} \).

### Step-by-Step Solution:

1. **Understanding the Probabilities**:
- Let \( x \) be the probability of guessing the correct answer.
- The probability of not guessing the correct answer is given as \( \frac{2}{3} \).

2. **Using the Property of Probabilities**:
- The sum of the probabilities of all possible outcomes must equal 1. In this case, the two outcomes are guessing correctly and guessing incorrectly.
- Therefore, we can write the equation:
\[ x + \frac{2}{3} = 1 \]

3. **Isolating \( x \)**:
- To find \( x \), we need to isolate it on one side of the equation. We can do this by subtracting \( \frac{2}{3} \) from both sides:
\[ x = 1 - \frac{2}{3} \]

4. **Calculating the Right Side**:
- To perform the subtraction, we need to express 1 as a fraction with a denominator of 3:
\[ 1 = \frac{3}{3} \]
- Now, substitute this into the equation:
\[ x = \frac{3}{3} - \frac{2}{3} \]

5. **Performing the Subtraction**:
- Now, subtract the fractions:
\[ x = \frac{3 - 2}{3} = \frac{1}{3} \]

6. **Final Answer**:
- Thus, the value of \( x \) is:
\[ x = \frac{1}{3} \]

### Summary:
The probability of guessing the correct answer is \( \frac{1}{3} \).