Exponential Growth: Logarithmic Applications in Real Life

A radioactive substance has a half-life of 5 years. If you start with 80 grams, how much will remain after 15 years?

• 10 grams

• 40 grams

• 20 grams

• 5 grams

A certain bacteria doubles in number every 3 hours. If you start with 500 bacteria, how many will there be after 12 hours?

• 1000

• 4000

• 16000

• 8000

A sample of a substance decays exponentially with a half-life of 10 days. If you have 200 mg of the substance, how much will be left after 30 days?

• 25 mg

• 50 mg

• 100 mg

• 10 mg

The half-life of a certain medication in the body is 4 hours. If a patient takes a dose of 200 mg, how much of the medication will remain in the body after 12 hours?

• 25 mg

• 100 mg

• 50 mg

• 75 mg

A tree's height increases exponentially. If a tree is 2 meters tall now and doubles in height every 5 years, how tall will it be in 15 years?

• 4 meters

• 16 meters

• 32 meters

• 8 meters

A certain isotope has a half-life of 3 years. If you have 160 grams of the isotope, how much will remain after 9 years?

• 100 grams

• 20 grams

• 80 grams

• 40 grams

A population of fish in a lake is currently 1,000. If the population doubles every year, how many fish will there be in 4 years?

• 2000

• 8000

• 4000

• 16000

A certain type of bacteria has a half-life of 2 hours. If you start with 1,000 bacteria, how many will be left after 6 hours?

• 750

• 250

• 500

• 125

A car depreciates in value exponentially, losing half of its value every 4 years. If the car is worth $20,000 now, what will its value be in 12 years?

• $15,000

• $5,000

• $2500

• $10,000

A certain chemical has a half-life of 8 days. If you start with 500 grams, how much will remain after 32 days?

• 250 grams

• 62.5 grams

• 125 grams

• 31.25 grams