A bag contains 12 yellow and 8 purple marbles. Joe pays $2

Last updated: 7/13/2022

A bag contains 12 yellow and 8 purple marbles. Joe pays $2 for the opportunity to pick a marble from the bag. If he picks a yellow marble, he does not get anything. If he picks a purple marble, he gets $k. The game is fair. Find the value of k. Give an exact answer. Do not include the dollar sign in your answer.