For a random variable \(x\), probability distribution \(P(x)\) is given by \(P(x) = \displaystyle\frac{k}{6}(3 - x), x = 0, 1, 2\), then
Match List-I with List-II
| List-I | List-II | ||
|---|---|---|---|
| (A) | \(k\) is equal to | (I) | \(\displaystyle\frac{1}{2}\) |
| (B) | \(P(x = 0)\) | (II) | 1 |
| (C) | \(P(x \lt 2)\) | (III) | \(\displaystyle\frac{1}{6}\) |
| (D) | \(P(1 \lt x \le 2)\) | (IV) | \(\displaystyle\frac{5}{6}\) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
The three probabilities are
\( \displaystyle P(0) = \frac{3k}{6},\quad P(1) = \frac{2k}{6},\quad P(2) = \frac{k}{6} \)
(A) \(k\) is equal to
This matches (II) 1. The probabilities add up to 1:
\( \displaystyle \frac{3k + 2k + k}{6} = k = 1 \)
So \(P(0) = \frac{1}{2}\), \(P(1) = \frac{1}{3}\), \(P(2) = \frac{1}{6}\).
(B) \(P(x = 0)\)
This matches (I) \(\frac{1}{2}\), as \(P(0) = \frac{3}{6}\).
(C) \(P(x \lt 2)\)
This matches (IV) \(\frac{5}{6}\). Here x is 0 or 1:
\( \displaystyle P(0) + P(1) = \frac{1}{2} + \frac{1}{3} = \frac{5}{6} \)
(D) \(P(1 \lt x \le 2)\)
This matches (III) \(\frac{1}{6}\). The only value of x with \(1 \lt x \le 2\) is x = 2, so the probability is \(P(2) = \frac{1}{6}\).
So the matching is (A)-(II), (B)-(I), (C)-(IV), (D)-(III).