Question

If e₁, e₂, e₃, e₄ are the four elementary outcomes in a sample space and P(e1) = 0.1, P(e₂) = 0.5, P(e₃) = 0.1, then the probability of e₄ is ______.

Answer 1

If e₁, e₂, e₃, e₄ are the four elementary outcomes in a sample space and P(e1) = 0.1, P(e₂) = 0.5, P(e₃) = 0.1, then the probability of e₄ is 0.3.

Explanation:

We know that the sum of all probabilities = 1

∴ P(e₁) + P(e₂) + P(e₃) + P(e₄) = 1

⇒ 0.1 + 0.5 + 0.1 + P(e₄) = 1

⇒ 0.7 + P(e₄) = 1

∴ P(e₄) = 1 – 0.7 = 0.3