8
lesson pretestMultiple Choice

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Question 8 • Mathematics III

If a raffle has a winning prize of 100 dollars and each ticket costs 5 dollars with a total of 500 tickets sold, which equation would calculate the expected value?

Answer
A
100 times open paren 1 over 500 close paren is equal to cap e times cap x
B
95 times open paren 1 over 500 close paren plus negative 5 times open paren 499 over 500 close paren is equal to cap e times cap x
C
open paren 100 minus 5 close paren times open paren 1 over 500 close paren is equal to cap e times cap x
D
100 times open paren 1 over 500 close paren plus negative 5 times open paren 499 over 500 close paren is equal to cap e times cap x

Explanation

The expected value uses the net outcome for each possibility. If the ticket wins, the $100 prize minus the $5 ticket cost gives a net gain of $95, with probability 1/500. If it loses, the net outcome is −$5, with probability 499/500, so choice C gives the correct calculation.

AI-written and checked against the verified answer.

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