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

# Answer

45
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
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?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
45
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?
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