What is the word or phrase?

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

What does this rebus riddle means ?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Prove that the below maths equation is true.

8 + 8 = 91

A man dies of old age on his 25 birthday. How is this possible?

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

Can you find the odd one out from the below words ?

First Second Third Forth Fifth Sixth Seventh, Eighth Nine Ten Eleven Twelve.

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

John and Jill are madly in love with each other. To remind Jill of his pure love, John wants to send her a ring by post but in their country where burglary is quite prominent, any package that is not locked comes under the risk of being stolen for the contents.

John and Jill possess many padlocks but neither one of them has the other key.

Can you find a way John can send the ring to Jill safely?