The expected value is $[tex]-2.23[/tex]
There are [tex]52[/tex] cards in a deck out of which [tex]13[/tex] are spades.
The probability that both cards are spade is
[tex]\frac{13}{52} \times \frac{12}{51} = 0.0588[/tex]
If both cards are spades, your friend will pay you $[tex]9[/tex]. Therefore, 0[tex].0588 \times 9 = 0.5292[/tex]
Probability that both are not spade [tex]= 1-0.0588 = 0.9412[/tex]
If both cards are not spades then you have to pay your friend $[tex]3[/tex]. Therefore, [tex]0.9412 \times -3 = -2.8236[/tex]
Here, negative sign represents the losses.
The expected value of your bet is: [tex]0.5292-2.8236=-2.2944[/tex]
Learn more here:
https://brainly.com/question/13005177