Good Riddles

 

Question: How can you make the following true by adding a single line: .9 = 1.

Note: ≠ is not the answer.

Question: You have an 8 by 8 chess board that has two corner squares diagonal from each other removed. Is there any way to place 31 dominoes of size 2x1 to cover the remaining 62 spaces?

3 coins (medium)

Question: You have three coins. One always comes up heads, one always comes up tails, and one is just a regular coin (has equal change of heads or tails). If you pick one of the coins randomly and flip it twice and get heads twice, what is the chance of flipping heads again?

Question: There are several different kinds, but the one you pick doesn't do its job.

What is it?

Riddle #1661 (medium)

Question: A man challenges you to a coin flipping contest. One of you must flip heads, then tails, then heads. The other must flip heads, then tails, then tails. Whoever succeeds in fewer flips is the winner.

Which should you choose?