conversations.from: human
conversations.value: Isaac cut his 30 meters ribbon into 6 equal parts. He then used 4 parts of the ribbon. How many meters of ribbon are not used?
  Give me a detailed solution.
conversations.from: assistant
conversations.value: Each part is 30/6 = 5 meters long.
  Since Liam used 4 parts, then he used 5 x 4 = 20 meters of the ribbon.
  So, 30 - 20 = 10 meters of ribbon is not used.