human
Rita is reading a five-chapter book with 95 pages. Each chapter has three pages more than the previous one. How many pages does the first chapter have?
assistant
Define a variable ** Let P be the number of pages in the first chapter.
How many pages does the second chapter have? ** The second chapter has P + 3 pages.
How many pages does the third chapter have? ** The third chapter has P + 3 + 3 = P + <<+3+3=6>>6 pages.
How many pages does the fourth chapter have? ** The fourth chapter has P + 6 + 3 = P + <<+6+3=9>>9 pages.
How many pages does the fifth chapter have? ** The fifth chapter has P + 9 + 3 = P + <<+9+3=12>>12 pages.
Write an equation ** The whole book has P + 3 + P + 6 + P + 9 + P + 12 = 5P + 30 = 95 pages.
How many pages are in the book? ** Thus, without the 30 extra pages from additional chapters, 5P = 95 - 30 = 65 pages.
How many pages does the first chapter have? ** Therefore, the first chapter had P = 65 / 5 = <<65/5=13>>13 pages.
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