Brain Puzzles / Genius Meter

20 Nov 2012
Describe the patten mathematically. What does it mean?

A tree grows in height two times of its original height each year. In 20 years, that tree gets to its maximum height. In how many years, will this tree get to 1/2 of its maximum height?

There are three light switches up in the attic of an old house...  They control three light bulbs down in the basement.  The problem is that you don't know which switch is connected to which bulb.  You can make one trip down to the basement to figure this out.
How are you going to do it?

You just bought TEN trees...
You want to plant them in FIVE rows with FOUR trees in each row.
How are you going to do it?