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

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

What does this Rebus Picture mean?

I can be cracked, made, told, and played. What am I?

What is the coolest letter in the alphabet?

If an earthquake is 1 point higher on the Richter Scale than another earthquake which is actually 10 times stronger, how much stronger would an earthquake be if it was just half a point higher on the Richter scale?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?