What is the fastest way to double your money?

I have eight fingers and two thumbs but I do not live. What Am I?

Alpha is Beta's sister.

Gamma is a Beta mother.

Delta is Gamma's father.

Tango is Delta's mother.

Then,

How is Alpha related to Delta?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

Can you spot the man between the coffee bean in the picture below ?

What is the next number in this matchsticks series riddle?

What is harder to catch the faster you run?

What number do you get when you multiply all of the numbers on a telephone's number pad?

During a secret mission, an agent gave the following code to the higher authorities
AIM DUE OAT TIE MOD

However, the information is in one word only and the rest are fake. To assist the authorities in understanding better, he also sent them a clue, If I tell you any one character of the code, you can easily find out the number of vowels in the codeword.

Can you find out the code word?

What do you call a fish without an eye?