Find the next number in the series below

21 32 54 87 131 ?

Why do people go to bed?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

What is the word or phrase?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

How can you drop a raw egg from a height onto a concrete floor without cracking it?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?