Exponential Function Solution Equation - Decay (Continuous, Mis-matched Time Units) - Scenario to Time

Level 1

The topics in this unit focus on mastering exponential growth and decay functions. Work on practice problems directly here, or download the printable pdf worksheet to practice offline.

Exponential Function Solution Equation - Decay (Continuous, Mis-matched Time Units) - Scenario to Time Worksheet

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Exponential Function Solution Equation - Decay (Continuous, Mis-match...
1
A toxin starts at a concentration of 200mg/L. It declines continuously at 8% per week. After a certain number of days it has decreased to a concentration of 134mg/L.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{134 over 200 }}{0.08}
b A LaTex expression showing t = -7 times 0.08 over \ln{\frac{134 {200}}}
c A LaTex expression showing t = +1 over 7 times \frac{\ln{134 times 200}}{0.08}
2
A radioactive material starts at an isotope concentration of 900ppm. It decays continuously at 5% per day. After a certain number of weeks it has decayed to an isotope concentration of 736ppm.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{736 over 900 }}{0.05}
b A LaTex expression showing t = -1 over 7 times \ln{\frac{736 over 900 }}{0.05}
c A LaTex expression showing t = +7 times \frac{\ln{736 times 900}}{0.05}
3
A bird population starts at 600. It declines continuously at 2% per year. After a certain number of quarters it has decreased to a population of 511.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -4 times 0.02 over \ln{\frac{511 {600}}}
b A LaTex expression showing t = -4 times \ln{\frac{511 over 600 }}{0.02}
4
A radioactive material starts at an isotope concentration of 600ppm. It decays continuously at 2% per week. After a certain number of days it has decayed to an isotope concentration of 501ppm.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{501 over 600 }}{0.02}
b A LaTex expression showing t = +1 over 7 times \frac{\ln{501 times 600}}{0.02}
5
A bacteria population starts at 600. It declines continuously at 5% per day. After a certain number of years it has decreased to a population of 542 bacteria.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -1 over 365 times \ln{\frac{542 over 600 }}{0.05}
b A LaTex expression showing t = +365 times \frac{\ln{542 times 600}}{0.05}
c A LaTex expression showing t = -365 times \ln{\frac{542 over 600 }}{0.05}
6
A radioactive material starts at an isotope concentration of 200ppm. It decays continuously at 9% per day. After a certain number of hours it has decayed to an isotope concentration of 97ppm.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = +1 over 24 times \frac{\ln{97 times 200}}{0.09}
b A LaTex expression showing t = -24 times \ln{\frac{97 over 200 }}{0.09}
c A LaTex expression showing t = -24 times 0.09 over \ln{\frac{97 {200}}}
d A LaTex expression showing t = -1 over 24 times \ln{\frac{97 over 200 }}{0.09}
7
A toxin starts at a concentration of 600mg/L. It declines continuously at 8% per week. After a certain number of days it has decreased to a concentration of 511mg/L.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -7 times \ln{\frac{511 over 600 }}{0.08}
b A LaTex expression showing t = -1 over 7 times \ln{\frac{511 over 600 }}{0.08}
c A LaTex expression showing t = -7 times 0.08 over \ln{\frac{511 {600}}}
8
A whale population starts at 500. It declines continuously at 9% per quarter. After a certain number of years it has decreased to a population of 266 whales.
Rearrange the exponential equation to solve for for the time given this scenario?
a A LaTex expression showing t = -4 times \ln{\frac{266 over 500 }}{0.09}
b A LaTex expression showing t = -1 over 4 times 0.09 over \ln{\frac{266 {500}}}
c A LaTex expression showing t = -1 over 4 times \ln{\frac{266 over 500 }}{0.09}