James builds a 20 story building.  The first 10 stories are each 12 feet tall each.  The remaining floors are each 3 feet taller.  How tall is the building?
How tall are the first 10 floors? ** The first 10 floors are 10*12=<<10*12=120>>120 feet
How many stories are left? ** There are a remaining 20-10=<<20-10=10>>10 stories
How tall are the remaining floors? ** They are each 12+3=<<12+3=15>>15 feet
How tall are the remaining floors? ** So those stories are 15*10=<<15*10=150>>150 feet
How tall is the building? ** So the total height is 120+150=<<120+150=270>>270 feet
#### 270