What is the fastest way to double your money?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

Which city is three-fifths chick two third cat and 50% goat?

What is the next number in the series?

15 29 56 108 208 ?

Can you write down eight eights so that they add up to one thousand?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

Name the three-letter word that can complete the below words?

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

What does the following BrainBat signifies?

ABCDEFGHIJKLMNOPQRSTUVWYZ

QQQQQQQQQQQQQQQQQQQQQQQQQ.

The more of this there is, the less you see. What is it?