CBSE Maths › Class 12 PYQs › Probability

Probability: 2 marks Questions (CBSE Class 12)

2 different 2 marks questions on Probability from CBSE Class 12 Maths board exams 2024–2026, newest first.

1 mark (26)2 marks (2)3 marks (31)4 marks (16)

Q252 marksVery Short AnswerProbability CBSE 2025 · 65/7/1Not in current syllabus

10 identical blocks are marked with ‘0’ on two of them, ‘1’ on three of them, ‘2’ on four of them and ‘3’ on one of them and put in a box. If X denotes the number written on the block, then write the probability distribution of X and calculate its mean.

Show answer & solution

Answer: X: 0, 1, 2, 3; P(X):

\frac{2}{10}, \frac{3}{10}, \frac{4}{10}, \frac{1}{10}

; mean = 1.4

X takes values 0, 1, 2, 3.
$P (X = 0) = \frac{2}{10}$ , $P (X = 1) = \frac{3}{10}$ , $P (X = 2) = \frac{4}{10}$ , $P (X = 3) = \frac{1}{10}$ .
Mean $= 0 \cdot \frac{2}{10} + 1 \cdot \frac{3}{10} + 2 \cdot \frac{4}{10} + 3 \cdot \frac{1}{10} = \frac{14}{10} = 1.4$ .

Also asked in: 2025 65/7/2, 2025 65/7/3

Q25 (OR) (OR)2 marksVery Short AnswerProbability CBSE 2025 · 65/7/1

In a village of 8000 people, 3000 go out of the village to work and 4000 are women. It is noted that 30% of women go out of the village to work. What is the probability that a randomly chosen individual is either a woman or a person working outside the village ?

Show answer & solution

Answer:

\frac{29}{40}

Let W: woman, O: works outside the village.
$P (W) = \frac{4000}{8000} = \frac{1}{2}$ , $P (O) = \frac{3000}{8000} = \frac{3}{8}$ .
Women working outside $= 30%$ of 4000 $= 1200$ , so $P (W \cap O) = \frac{1200}{8000} = \frac{3}{20}$ .
$P (W \cup O) = \frac{1}{2} + \frac{3}{8} - \frac{3}{20} = \frac{20 + 15 - 6}{40} = \frac{29}{40}$ .

Also asked in: 2025 65/7/2, 2025 65/7/3

← Linear Programming

Practise smarter: chapter-wise revision, formula sheets and step-by-step NCERT solutions on MonoMath CBSE →