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

Can you find out the missing number in the grid?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

When it's bad luck to meet a black cat?

It was a dark stormy night and a couple were in a car driving madly to a city. The car broke down and the husband had to go get help from someone who spoke his language. He was afraid to leave his wife alone in the car so he locked the car before leaving. When he came back, the car was in the same state as he had left it but his wife was dead, there was blood on the floor and there was a stranger in the car. What happened?

Can you find the six hidden animals in the picture below?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

I went to the bookshop and spent one-half of the money that was in my purse.

When I came out, I found that I had as many cents as I had dollars and half as many dollars as I had cents when I went in. Find the money in my purse when I entered the store.

If a boy blows 18 bubbles,
Then pops 6 eats 7 and then
He pops 5 and blows 1.
How many are left?

What is the below Rebus indicate?