How many bananas can you eat if your stomach is empty?

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

What has hands, but can’t clap?

One of the leprechaun is missing if you see the two pictures attached to this question. Where did he go? When he comes back, do you know where has he been?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

What are the next two letters in the following series and why?
W A T N T L I T F S _ _

*Hint: Check Puzzle Title

A beggar on the street can make one cigarette out of every 6 cigarette butts he finds. After one whole day of searching and checking public ashtrays the beggar finds a total of 72 cigarette butts. How many cigarettes can he make and smoke from the butts he found?

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?