Count the number of triangles in the picture below:

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

Prove that twice of ten is the same as twice of eleven.

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Can you find the hidden animal in the picture below?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Replace the question mark with the correct number in the below-given picture?

A wooden log balances equally on the scales when weighed with three-quarters of a pound and three-quarters of a wooden log.

Can you calculate the weight of the entire wooden log?

James ordered a fishing rod, priced at $3.56. Unfortunately, James is an Eskimo who lives in a very remote part of Greenland and the import rules forbid any package longer than 4 feet to be imported. The fishing rod was 4 feet and 1 inch, just a little too long, so how can the fishing rod be mailed to James without breaking the rules? Ideally James would like the fishing rod to arrive in one piece!