Last year, the school library purchased 50 new books. This year, it purchased 3 times as many books. If the library had 100 books before it purchased new books last year, how many books are in the library now?
Last year, there were a total of 100 + 50 = <<100+50=150>>150 books in the library.
The library purchased 50 x 3 = <<50*3=150>>150 books this year.
Therefore, the library now has a total of 150 + 150 = <<150+150=300>>300 books.
#### 300