Can you make four (4) nines (9) equal 100?

People make me, save me, change me, raise me. What am I?

Find the combined weight of the Cat, Dog and Rabbit in the given picture.

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

John went to meet his friend Jacob, but when he was about to reach the main gate, John notices that Jacob had a mighty dog who was fastened to the tree. The chain is long enough that it allows the dog to reach the main gate.

How can the John reach the main gate?

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.

The picture shows the dice results in each couple of throws. If they are actually following a pattern, can you find out the missing one?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different.

How do you measure 45 minutes?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

How many bananas can you eat if your stomach is empty?