Trick of Mind

This question is probably older than I. A man leaves his camp and travels due south for 3 miles. He then heads due west for 7.5 miles. He now heads due north for another 3 miles and spots a bear rummaging through his tent. What color is the bear?

You have a hand of cards that depict each of the letters of the alphabet. You fan the cards and see they are in the following order:
F, W, X, Y, Z, K, L, A, T, U, J, N, O, S, D, E, P, V, C, B, G, H, I, Q, R, M
Your job is to [...]

Four glasses are placed upside down in the four corners of a square
rotating table.
You wish to turn them all up. You may do so by grasping any two glasses and, optionally, turning either over.
There are two catches:
1. you are blindfolded
2. the table is spun after each time you move the glasses
Assuming that a bell [...]

Chris has just started a new company selling weighing instruments – “Chris-Mass”. (Geddit?!?! Christmas – Chris-Mass, you know – weight!?!? – sometimes I excel myself!)
His first order has just been shipped to you. It comprises of a super-accurate beam balance and a 40 lb. rock, this system will allow you to accurately weigh items from [...]

The wily explorer Knightmare, and his trusty companion, Slavy have scoured the deserts of the world in search of the fabled Icosahedron Diamond. Hundreds of miles from civilization, they discover the aforementioned bauble, a beautiful giant crystal worth a King’s ransom.
Unfortunately, the diamond is on a tiny island in the centre of a perfectly [...]

If you are walking southbound on a northbound bus, in how many directions are you traveling at that moment in time, ignoring micromovements? You must explain your answer.

A well{known logical joke is a card saying on one side “The statement
on the other side is false” and on the other, “The statement on the
other side is true”. Clearly, it is impossible for either of the statements
to be true or false without leading to an inconsistency. However, if
both sides said “The statement on the [...]

I received my set of twelve balls from the pool hall, so that I could test my solution to the twelve ball problem. But when I opened the box I saw to my horror that the manufacturer had included three extra balls! Now I had 15 identical looking balls, only one of which is either [...]

During WWII, the Royal Air Force called upon a mathematician to improve their bombers. Specifically, they wanted to reduce the chances of them being shot down.
Bombers are relatively slow moving targets escorted by smaller fighters to protect them from air attacks. But antiaircraft fire would occasionally knock them down.
So a reasonable solution was [...]

You are a weapons manufacturer and you have just developed a gun that fires a bullet at 0.9c (c is the speed of light, y’know – e=mc2 and all that…?)
You are having a chat with a friend of yours who has just developed a new car that travels at 0.9c (It’s a Toyota Avensis…)
During this [...]