Answer:
c
Step-by-step explanation:
Let number of books by astrid's = x
Out of x , 84% are fiction.
So, Number of non fictional books = x - 
= 
→Ratio of number of books to fictional books
⇒[Dividing numerator and denominator by 4.]
→Out of 25 books by astrid 21 are fictional.
→ Number of fictional books by astrid = 
Answer:
B. 31r − 71 is the answer!