A water sample initially contains ppm of pollutant C
MATHEMATICS · Single correct · AP · AP Precalculus · Exponential and Logarithmic Functions · Exponential and Logarithmic Functions
Problem
A water sample initially contains 500 ppm of pollutant C, which decays continuously at rate 0.08 h−1. Simultaneously, pollutant D is introduced at an initial concentration of 50 ppm and increases continuously at rate 0.05 h−1. Which of the following best describes when the two concentrations are equal and which pollutant has the greater concentration two hours afterward?
(a) They are equal at approximately 10.6 h; thereafter pollutant D has the greater concentration.
(b) They are equal at approximately 17.7 h; thereafter pollutant D has the greater concentration.
(c) They are equal at approximately 17.7 h; thereafter pollutant C has the greater concentration.
(d) They are equal at approximately 7.7 h; thereafter pollutant D has the greater concentration.