John plants a plot of 3 trees by 4 trees.  Each tree gives 5 apples.  He sells each apple for $.5.  How much money does he make, in dollars?
He has 3*4=<<3*4=12>>12 trees
So he has 12*5=<<12*5=60>>60 apples
So he sells the apples for 60*.5=$<<60*.5=30>>30
#### 30