Betty has 20 books, and her sister has 1/4 times more books than Betty. What's the total number of books the two have?
Betty's sister has 1/4 * 20 books = <<1/4*20=5>>5 more books.
The total number of books Betty's sister has is 20 books + 5 books = <<20+5=25>>25 books
The total number of books the two have is 25 books + 20 books = <<25+20=45>>45 books
#### 45