How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Jim and Sarah are in a long-distance relationship. Jim buys an engagement ring for Sarah and wants to mail it to her. Unfortunately, the only way to ensure the ring will be received is to place a lock on the package. Jim has locks and Sarah has locks, but neither has keys for each other’s locks. How can they make sure the ring isn’t stolen?

Take away the whole and some still remain. What is it?

Can you find out who is the kidnapper in below Picture and why, Explain ?