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MHT CET · Maths · Probability

A fair coin is tossed 2 times. A person receives \(₹ X^{3}\) if he gets \(X\) number of heads.
His expected gain is \(=\)

  1. A \(₹ 2.00\)
  2. B \(₹ 1.00\)
  3. C \(₹ 2.50\)
  4. D \(₹ 5.20\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(₹ 2.50\)

Step-by-step Solution

Detailed explanation

A fair coin is tossed 2 times. Possible outcomes are HH, HT, TH, TT \(\therefore X\) takes values \(0,1,2\)
\(\therefore P(X=0)=\frac{1}{4}, P(X=1)=\frac{2}{4}=\frac{1}{2}, P(X=2)\) \(=\frac{1}{4}\)
Given a person receives \(₹ X^{3}\) if we gets \(X\) no. of heads.
\( \therefore \text {Expected gain }=\left(\frac{1}{4} \times 0\right)+\left(\frac{1}{2} \times 1^{3}\right)~+\) \(\left(\frac{1}{4} \times 2^{3}\right) \)
\(=0+\frac{1}{2}+\frac{8}{4}=2.5\)