Find the next number in the sequence

1, 2, 6, 21, 88, __?

A plane crashed between the border of Mexico and America. Where do you bury the survivors?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

What always comes into a house through the keyhole?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Find three numbers such that

* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.

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