conversations.from: human
conversations.value: Can you explain how to solve this math problem: Devin teaches one math course per year. He taught Calculus for 4 years, Algebra for twice as many years, and Statistics for 5 times as long as he taught Algebra. How many years has Devin taught?
conversations.from: assistant
conversations.value: Calculus: 4 years
  Algebra: 4(2)=8 years
  Statistics: 8(5)=40 years
  Total number of years taught: 4+8+40=52 years