A person throws two fair dice.

Question

A person throws two fair dice. He wins Rs. 15 for throwing a doublet (same numbers on the two dice), wins
Rs. 12 when the throw results in the sum of 9, and loses Rs. 6 for any other outcome on the throw. Then the
expected gain/loss (in Rs.) of the person is :

Accepted Answer

When two dice are thrown then sample space will {(1, 1), (2, 2) ....... (6, 6)} contain total 36 elements number of cases.

Then the expectation will be $${6 \over {36}} \times 15 \times {4 \over {36}} \times 12 - {{26} \over {36}} \times 6$$

$${{90 + 48 - 156} \over {36}} =  - {1 \over 2}$$ = $$ {1 \over 2}$$ loss

Solutions · 1