Exponential Decay and Growth Word Problems

What does "t" stand for in the exponential growth formula?

• final amount

• time

• original amount

• rate of growth

Marburn has 80 total students in our High School. It is projected to grow at rate of 2% every year. How many students will be in the High School in 5 years from now?

• 72.3 students

• 88.3 students

• 199.1 students

• 80 students

The population of a town is decreasing at a rate of 5% per year. This year there are 10,000 people in this town, how many people will be left in 20 years from now? (round to the nearest whole number)

• 26,533 people

• 358 people

• 1 person

• 3,585 people

What does "r" stand for in the exponential growth formula?

• final amount

• time

• original amount

• rate of growth

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What is the population of the town 21 years later?

• 6191

• 9912

• 72519

• 14108

The foundation of your house has about 1,200 termites. The termites grow at a rate of about 2.4% per day. How long until the number of termites doubles? T(d)=1200(1.024)^d

• 29 to 30 years

• 23 to 24years

• 15 to 16 years

• 19 to 20 years

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the population of rabbits after 6 months if the population triples every month and initially there are 50 rabbits.

• 50000

• 145800

• 3000

• 800

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the population of bacteria after 5 hours if it doubles every hour and initially has 100 bacteria.

• 500

• 3200

• 2000

• 1000

The foundation of your house has about 1,200 termites. The termites grow at a rate of about 2.4% per day. How long until the number of termites doubles?

• 29 to 30 days

• 23 to 24 days

• 15 to 16 days

• 19 to 20 days

Using the exponential function equation f(x)=ab^x, where a is the starting value and b is the growth or decay, and x is the time, find the population of fish after 8 weeks if the population doubles every week and initially there are 1000 fish.

• 128000

• 512000

• 64000

• 256000