conversations.from: human
conversations.value: Provide a step by step solution for the following math problem: Nico borrows 3 books from the library on Monday.  On Monday, he reads the first book with a total of 20 pages.  On Tuesday, he reads the second book with a total of 12 pages.  On Wednesday, he reads the third book.  If he has read a total of 51 pages from Monday to Wednesday, how many pages did he read on Wednesday?
conversations.from: assistant
conversations.value: From Monday to Tuesday, Nico reads a total of 20 + 12 = 32 pages.
  On Wednesday, he read a total of 51 - 32 = 19 pages.