What happened when the wheel was invented?

What part of Turkey has the most feathers?

How many triangles can you find in this given picture?

What can go up a chimney down, but can’t go down a chimney up?

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.

Forwards I am heavy, backward I am not. What am I?

Can you replace the question mark with the correct number?

Consider this: Arnold Schwarzenegger has a big one. Michael J. Fox has a small one. Prince doesn’t have one. The Pope has one but never uses it. Bill Clinton has one and uses it all the time. What is it?

I have branches, but no fruit, trunk or leaves. What am I?

What does this below rebus puzzle mean?