A frog is at the bottom of a 30-meter well. Each day he summons enough energy for one 3-meter leap up the well. Exhausted, he then hangs there for the rest of the day. At night, while he is asleep, he slips 2 meters backwards. How many days does it take him to escape from the well?

What question can you never answer yes to?

A man comes across a coin that is dated 226 B.C. Can you calculate its worth?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

There is a brick of gold and a brick of iron in a boat (both 10-inch blocks), if they are both dropped into the water which will make the water level higher?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

What number divided by 4 is the same as that number minus 4?

What two things can you never eat for breakfast?

Name a key which is hardest to turn.