Question

Kim is reading a book with 380 pages. She read 20 pages each day until she reached Part 2 of the book. Part 2 of the book is 160 pages long. She uses the equation 380−20d=160 to represent the number of days, d, it took her to read Part 1. How many days did it take Kim to read Part 1 of the book?

Answer 1

380-20d=160

⇒20d=220

⇒d=11

Thus it took Kim 11 days to read part 1 of the book.