conversations.from: human
conversations.value: Explain how to solve this math problem: Luis needed to buy some socks. He bought 4 pairs of red socks and 6 pairs of blue ones. In total, he spent $42. If the red socks cost $3 each, how much did he pay for each blue pair?
conversations.from: assistant
conversations.value: Let B be the cost of the blue socks
  4*3 +6*Y =42
  12 + 6*Y=42
  6*Y =30
  Y = 5