Question

There are 10 cards, labeled from 1 to 10, lying face down on a table. You pick a card, and if that card is a 10, you win $20. If the card is not 10 you win $0. What is the expected amount you would win (in dollars)?

Answer 1

idk i think its 20

Answer 2

bt thats to obvious right

Answer 3

expected value is the amount you win times the probability you win it (with the sophistication that you can win a negative amount of money)

Answer 4

in this case it is \[20\times \frac{1}{10}=2\]

Answer 5

thanks I ll try it

Answer 6

its right

Answer 7

you can also think like this
pick all 10 cards, you win $20 and lose nothing
averaged over the total number of picks you won \(\frac{20}{10}=2\) per pick

Answer 8

I check I know its right thanks alot man

Answer 9

yw