Before Mount Everest was discovered, what was the highest mountain in the world?

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

A guard is positioned at the one side of the bridge saying ‘A’. His task is to shoot all those who try to leave from ‘A’ to the other side and say ‘B’. He also need to welcome the person who comes from another side ‘B’ to his side ‘A’. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side ‘A’ and wish to go to another side ‘B’. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?

If eleven plus two equals one, what does nine plus five equal?

My location can be determined by the below rebus.
So where am i ?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

He digs out tiny caves and stores gold and silver in them. He also built bridges of silver and made crowns of gold. They are the smallest you could imagine. Sooner or later everybody needs his help, yet many people are afraid to let him help them. Who is he?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Can you count the number of quadrilaterals in the picture below?

What does the rebus below mean?

TEN BADTION