GAUSS7 2010 Problem 22

In the Coin Game, you toss three coins at the same time. You win only if the 3 coins are all showing heads, or if the 3 coins are all showing tails. If you play the game once only, what is the probability of winning?

Answer Choices
A. \frac16
B. \frac14
C. \frac{2}{27}
D. \frac23
E. \frac13