Question

Your friend hides a dollar bill under one of three plastic cups. Under the other

two cups is a paper clip. You get to keep whatever is under the cup you
choose, but you don't know which contains the dollar bill. After you choose,
your friend lifts one of the other cups to reveal a paper clip and then gives you
the option of changing your choice.
Should you switch to the other cup?

Answer 1

Yes, you should

Explanation:

Because the probability of winning the dollar increases from \frac{1}{3} 3 1​ to \frac{2}{3} 3 2​ by switching.