Question 188462
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Let <i>x</i> be the number of wins.  Then, if there were 30 plays, there must have been 30 - <i>x</i> losses.  The total amount returned would be $2 times the number of wins minus $1 times the number of losses, and this must be equal to -$6:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ 2x - (30 - x) = -6 \ \ \Rightarrow\ \ 2x + x = - 6+ 30 \ \ \Rightarrow\ \ 3x = 24 \ \ \Rightarrow\ \ x = 8]


Check:

8 wins returns $16.  30 - 8 = 22 losses loses $22.   $16 - $22 = -$6.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
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