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?

Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

Can you tell a 3D object that has just two surfaces?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

In front of you, there are 9 coins. They all look absolutely identical, but one of the coins is fake. However, you know that the fake coin is lighter than the rest, and in front of you is a balance scale. What is the least number of weightings you can use to find the counterfeit coin?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

How many letters are in the alphabet?

Which is faster, Heat or Cold ? Explain.

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

Why do people go to bed?