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

John went to buy some expensive, foreign chocolates. He only had Rs 100 with him. When he reached the shop, he got out and know that on those chocolates, there was a 15% import duty and 5% VAT.

How much worth chocolate should he buy so that he can accommodate it in Rs 100?

Can you find the 09 errors in the picture below?

Can you spot the hidden girl in the picture below?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

What kind of storm is always in a rush?

Can you solve below mathematical equation?

2^1234 - 2^1233

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Three men in a cafe order a meal the total cost of which is $15. They each contribute $5. The waiter takes the money to the chef who recognises the three as friends and asks the waiter to return $5 to the men.

The waiter is not only poor at mathematics but dishonest and instead of going to the trouble of splitting the $5 between the three he simply gives them $1 each and pockets the remaining $2 for himself.

Now, each of the men effectively paid $4, the total paid is therefore $12. Add the $2 in the waiters pocket and this comes to $14. Where has the other $1 gone from the original $15?