conversations.from: human
conversations.value: I would love to understand how to solve this problem: Bill is trying to dig a well in his backyard. He can dig 4 feet/hour through soil and half that fast through clay. If he has to dig through 24 feet of soil and 8 feet of clay, how long will it take him to dig the well?
  Can you explain?
conversations.from: assistant
conversations.value: First find how fast Bill can dig through clay: 4 feet/hour / 2 = 2 feet/hour
  Then find how long he spends digging through clay in total: 8 feet / 2 feet/hour = 4 hours
  Then find how long he spends digging through soil in total: 24 feet / 4 feet/hour = 6 hours
  Then add the time he spends digging through soil and clay to find the total digging time: 4 hours + 6 hours = 10 hours