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MathsJEE Main 21 Jan 2026, Shift 2·Q10·MCQ·Moderate

Probability · Mean and variance of distribution

A random variable XX takes values 0, 1, 2, 3 with probabilities 2a+130,8a−130,4a+130\dfrac{2a+1}{30}, \dfrac{8a-1}{30}, \dfrac{4a+1}{30}, bb respectively, where a,b∈Ra, b \in \mathbb{R}. Let μ\mu and σ\sigma respectively be the mean and standard deviation of XX such that σ2+μ2=2\sigma^2 + \mu^2 = 2. Then ab\dfrac{a}{b} is equal to:
  1. (1)30
  2. (2)3
  3. (3)60
  4. (4)12

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