Sophia finished 23 of a book. She calculated that she finished 90 more pages than she has yet to read. How long is her book?	Choose the correct choice from the following choices
A) 180
B) 200
C) 250
D) 270
E) 300

Rationale: "let x be the total number of pages in the book , then she finished 23 ⋅ x pages . then she has x − 23 ⋅ x = 13 ⋅ x pages left . 23 ⋅ x − 13 ⋅ x = 90 13 ⋅ x = 90 x = 270 . so answer is d ."
Answer: D