conversations.from: human
conversations.value: Can you break down the solution for me for this math problem: The ratio of books to pens that Arlo has to buy for his school supplies is 7:3. If he bought a total of 400 stationery from the store, calculate the number of books he bought.
conversations.from: assistant
conversations.value: The total ratio representing the stationery that Arlo has to buy for his school supplies is 7+3 = 10
  The fraction representing the number of books that Arlo bought is 7/10, and since he bought a total of 400 books and pens, he bought 7/10*400 = 280 books.