Question

You are challenged to a lucky draw game. If you draw a face card (K, Q, J) from a standard deck of cards, you earn 10 points. If you draw any other card, you lose 2 points. What is the expected value of a draw?

Answer 1

52 cards in a standard deck

Answer 2

as a general formula

expected value = \[\sum_{}^{}(probability~of~event)(value~of~event)\]

applying the logic to this problem,

expected value = (probability of drawing a face card)(point value of drawing a face card) + (probability of not drawing a face card)(point value of not drawing a face card)