A Biologist Measures the Amount of Contaminant in a Lake

Short Answer

A biologist measures the amount of contaminant in a lake 3 hours after a chemical spill and again 11 hours after the spill. She sets up a possible model to determine Q, the amount of the chemical remaining in the lake as a function of t, the time in hours since the spill. The model assumes the contaminant is leaving the lake at a constant rate, which she determines to be 6 tons/hour. She estimates that the lake will be free from the contaminant 30 hours after the spill. How many tons of the contaminant were in the lake at the 3 hour reading?