What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

In the given picture, in how many ways can you read the word "Tiger"?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

Take number 1000 and then add 20 to it.
Now add 1000 one more time.
Now add 30.
Now add 1000 one more time.
Now add 40.
Now add 1000 one more time.
Now add 10.

What is the total?

How many triangles are there in the picture below?

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Sachin bought a car with a strange 5 digit numbered plate.The water image of the number is 78633 more than my car number. All the digits of car number are distinct.

What is the original number on number plate?