A dead body was found with a closed room of a house where the temperature
was a constant 70°F. At the time of discovery the core temperature of the body
was determined to be 85°F. One hour later a second measurement showed that
the core temperature of the body was 80°F. Assume that the time of death
corresponds to t = 0, and that the core temperature at that time was 98.5°F.
Determine how many hours elapsed before the body was found. [Hint: Let t1 >
0 denote the time that the body was discovered.]