conversations.from: human
conversations.value: Can you explain how to solve this math problem: The file, 90 megabytes in size, downloads at the rate of 5 megabytes per second for its first 60 megabytes, and then 10 megabytes per second thereafter. How long, in seconds, does it take to download entirely?
conversations.from: assistant
conversations.value: The first 60 megabytes take 60/5=12 seconds.
  There are 90-60=30 remaining megabytes.
  The remaining 30 megabytes take 30/10=3 seconds.
  And 12+3=15 seconds.