Hard Riddles and Answers

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?

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?

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?

Question: What do you use to hoe a row, slay a foe, and wring with woe?

Question: You are in a car with some helium balloons and hit the gas. While you accelerate, which way does the balloon move?

Question: You're going to a friends house and want to give them some brownies. On the way to their house you cross 5 bridges. At each bridge you must pay a toll of half of your brownies to the owner. But they are all very nice and give you back a brownie from what you give them.

How many brownies must you start with to give your friend 2 brownies?

Question: Two men, Watson and Holmes, are out in the extremely dry forest. They are completely surrounded by a large forest fire on one side and a dangerous cliff on the other. The wind is blowing the forest fire towards them and the cliff. The fire will reach them in about one day.

Holmes turns to Watson, "I have matches, berries, and enough water for a day. We aren't going to die." How can they avoid getting swallowed up by the forest fire?

Question: A father's child. A mother's child. no one's son.

Who am I?