Computation

Using the numbers 3,3,8, and 8 in any order and using only +, -, x, and (), is it possible to construct an equation that equals 24? If such an arrangement is possible, how would it be accomplished?

Sandglasses: Timing II

You have two sandglasses – one measures 7 minutes and the second measures 4 minutes. Is it possible to correctly time 9 minutes? If so, how?

Fractions

Arrange the numbers 1, 2, 3, 4, 5, 6, 7, 8, and 9 using one numeral only once above and below a division line to form the fraction 1/3. If the arrangement is possible, show how!

Credit to BrainDen

If you choose an answer to this question, what’s the chance you will be correct?

a) 25%

b) 60%

c) 50%

d) 25%

‘The Hardest Logic Problem, Ever?’

This problem is very famous and has gained great attention nationwide. It’s even been called “The Hardest Logic Problem, Ever” by some. It has been found on various reputable sites like PuzzleYourself, and has even been posted on Harvard Review of Philosophy by the logician George Boolos. Enjoy solving!

Three gods A, B, and C are called, in no particular order, True, False, and Random. True always speaks truly, False always speaks falsely, but whether Random speaks truly or falsely is a completely random matter. Your task is to determine the identities of A, B, and C by asking three yes or no questions; each question must be put to exactly one god. The gods understand English, but will answer all questions in their own language, in which the words for yes and noare da and ja, in some order. You do not know which word means which.

Further Clarifications

• It could be that some god gets asked more than one question (and hence that some god is not asked any question at all).
• What the second question is, and to which god it is put, may depend on the answer to the first question. (And of course similarly for the third question.)
• Whether Random speaks truly or not should be thought of as depending on the flip of a coin hidden in his brain: if the coin comes down heads, he speaks truly; if tails, falsely.

Six Coins

Six Coins

There are six coins arranged into a cross, as shown above. Is it possible to move one coin to make a cross such that there are four coins in each row?

Credit to D.Russell

The 3 Way Duel

This is a famous logic problem posted throughout the internet on many different blogs. We appreciate you taking the time to read it on PuzzleYourself, but if you do comment on the question, please take the time to it yourself. Thank You!

Mr. Black, Mr. Gray, and Mr. White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr. Black, who hits his shot 1/3 of the time, gets to shoot first. Mr. Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr. White, who hits his 100 percent of the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr. Black, where should you shoot first for the highest chance of survival?