Tim buys a book of esoteric words.  He learns 10 words from it a day.  In 2 years the book has increased the number of words he knows by 50%.  How many words did he know originally?
In 2 years there are 365*2=<<365*2=730>>730 days
So he has learned 730*10=<<730*10=7300>>7300 words
He knew 1/.5=2 times that number of words before the book
So he knew 7300*2=<<7300*2=14600>>14600 words before
#### 14600