conversations.from: human
conversations.value: Can you give me some step-by-step instructions for this math problem: June has $500 for buying school supplies for the new school year. She buys four maths books at $20 each, six more science books than maths books at $10 each, and twice as many art books as maths books at $20 each. If she also bought music books, how much money did she spend on music books?
conversations.from: assistant
conversations.value: The total cost of maths books is 4*20 = $80$.
  She bought six more science books than maths books which totals 6+4 = 10 books.
  If each science book cost her $10 she spent 10*10 = $100 on science books.
  There were twice as many art books as maths books which total 2*4 = 8
  The total cost for art books is 8*20 = $160
  The total amount that she used for maths, science, and art books is 160+100+80 = $340
  The amount she spent on music books is 500 - 340 = $160