conversations.from: human
conversations.value: I'm stuck on this math problem: Rob, Royce, and Pedro are contractors getting ready to put a new roof on three homes. If the three homes will need 250 cases of shingles, with the first house needing 1/2 of the second, and the third needing double the first. How many cases of shingles will the third house need?
  Can you help?
conversations.from: assistant
conversations.value: Let x be the number of cases of shingles for the second house
  The first house needs 1/2 x cases of shingles
  The third house needs 2(1/2)x=x cases of shingles
  250=x+x+(1/2)x
  250=(5/2)x
  250(2/5)=100=x
  The third house needs 100 cases of shingles