To address the problem, we will first define the given probabilities and then calculate the required probability through a series of steps:
- The probability of Ajay's absence from the JEE exam is given as \(p = \frac{2}{7}\). Consequently, the probability of Ajay's attendance is \(1 - p = 1 - \frac{2}{7} = \frac{5}{7}\).
- The probability that both Ajay and Vijay attend the exam is given as \(q = \frac{1}{5}\).
- Our objective is to determine the probability that Ajay attends the exam while Vijay does not. This can be represented as \(P(A \cap V')\).
- Using the principle of total probability for Ajay's attendance:
- We have the equation \(P(A \cap V) + P(A \cap V') = P(A)\).
- Substituting the known values into the equation yields: \(\frac{1}{5} + P(A \cap V') = \frac{5}{7}\).
- We now solve the equation for \(P(A \cap V')\):
- Rearranging the equation, we get \(P(A \cap V') = \frac{5}{7} - \frac{1}{5}\).
- To perform the subtraction of these fractions, we find a common denominator, which is 35:
- The fractions are converted as follows: \(\frac{5}{7} = \frac{25}{35}\) and \(\frac{1}{5} = \frac{7}{35}\).
- Therefore, the subtraction results in \(P(A \cap V') = \frac{25}{35} - \frac{7}{35} = \frac{18}{35}\).
The probability that Ajay attends the exam and Vijay does not is \(\frac{18}{35}\).
The confirmed answer is \(\frac{18}{35}\).