Expected value

Rarely Tested

The expected value (mean) of a discrete random variable is given by:
$$E(X) = \sum x_iP(X = x_i)$$

where,

$$x_i :$$ Possible values of random variable

$$P(X = x_i) :$$ Probability of obtaining $$x_i$$

Question 1

Ashish is betting on a card game where two cards are drawn randomly from a deck of cards. If both cards are face cards he gets Rs 10. If one of them is a face card he gets Rs 2. Else he has to pay the dealer Rs 1. How much can we expect Ashish to make from this game?

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