Use the numbers 2, 3, 4 and 5 and the symbols + and = to make a true equation. Conditions: Each must be used exactly once and no other numbers or symbols can be used.
* When we multiply three numbers, we will get the prime numbers.
* The difference between the second and the first number is equal to the third and second.
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?
How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?