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If the random variable XX has the following distribution:

XX012otherwise
P(X)P(X)kk2k2k3k3k00

Match List-I with List-II:

List-IList-II
(A) kk(I) 56\frac{5}{6}
(B) P(X<2)P(X < 2)(II) 43\frac{4}{3}
(C) E(X)E(X)(III) 12\frac{1}{2}
(D) P(1≤X≤2)P(1 \leq X \leq 2)(IV) 16\frac{1}{6}

Solution

✅ Correct Option: 2

First, we need to find the value of kk.

For any probability distribution, the sum of all probabilities must equal 1:

P(X=0)+P(X=1)+P(X=2)=1P(X = 0) + P(X = 1) + P(X = 2) = 1

k+2k+3k=1k + 2k + 3k = 1

6k=16k = 1

k=16k = \dfrac{1}{6}


Next, let's find P(X<2)P(X < 2):

P(X<2)=P(X=0)+P(X=1)P(X < 2) = P(X = 0) + P(X = 1)

P(X<2)=k+2k=3k=3⋅16=12P(X < 2) = k + 2k = 3k = 3 \cdot \dfrac{1}{6} = \dfrac{1}{2}


For the expected value E(X)E(X):

E(X)=∑[x⋅P(X=x)]E(X) = \sum[x \cdot P(X = x)]

E(X)=0⋅k+1⋅2k+2⋅3kE(X) = 0 \cdot k + 1 \cdot 2k + 2 \cdot 3k

E(X)=2k+6k=8k=8⋅16=43E(X) = 2k + 6k = 8k = 8 \cdot \dfrac{1}{6} = \dfrac{4}{3}


For P(1≤X≤2)P(1 \leq X \leq 2):

P(1≤X≤2)=P(X=1)+P(X=2)P(1 \leq X \leq 2) = P(X = 1) + P(X = 2)

P(1≤X≤2)=2k+3k=5k=5⋅16=56P(1 \leq X \leq 2) = 2k + 3k = 5k = 5 \cdot \dfrac{1}{6} = \dfrac{5}{6}


Matching the lists:

(A) k=16k = \dfrac{1}{6} matches with (IV)

(B) P(X<2)=12P(X < 2) = \dfrac{1}{2} matches with (III)

(C) E(X)=43E(X) = \dfrac{4}{3} matches with (II)

(D) P(1≤X≤2)=56P(1 \leq X \leq 2) = \dfrac{5}{6} matches with (I)

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