Question: thabo owns exactly 180 books , and each book is either paperback fiction , paperback nonfiction , or Hardcover nonfiction . if he owns 20 more paperback nonfiction books than Hardcover nonfiction books , and twice as many paperback fiction books as paperback nonfiction books , how many Hardcover books nonfiction books does thabo own ?
A) 10
B) 20
C) 30
D) 40
E) 50
Correct answer: C
Grade: 6 | Topic: Expressions and Equations | Difficulty: Medium | Standard: 6.EE.C.9