Exponential Functions Growth and Decay Word Problems

Is this exponential growth or decay?

• Growth because a=1

• Growth because there is no a

• Decay because b=0.5

• Neither because a=0

The value of a car is $15,000 and depreciates at a rate of 8% per year. What is the exponential equation?

• y=8(15,000)^x

• y=15,000(0.92)^x

• y=15,000(1.08)^x

• y=15,000(0.08)^x

Is the pictured graph exponential growth, exponential decay, or linear or none?  

• Exponential Growth

• Exponential Decay

• Linear

• None of the above

What is the initial value?

• 0

• 3

• 33

• 66

A population of bacteria can be modeled by the function f(t) = 1000 (0.95)^t, where t represents the time since the population started decaying, and f(t) represents the population of the remaining bacteria at time t. What is the rate of decay for this population?

• 95%

• 5%

• 0.95%

• 0.05%

When a ball is dropped from the top of a roof, the height of the ball decreases by 15% with each bounce. If the height of the ball started at 80 inches, which function can be used to find the height of the ball after 4 bounces?

• h(t) = 80(1 + 0.015)^4

• h(t) = 80(1 - 0.015)^4

• h(t) = 80(1 - 0.15)^4

• h(t) = 80(1 + 0.15)^4

In the formula f(t) = (9.05 × 10^6)(1.031)^t, what does 9.05 × 10^6 represent?

• Initial population

• Growth rate

• Time period

• Final population

Which of the following is true about exponential growth and decay?

• Growth factors are greater than 1, decay factors are less than 1

• Growth factors are less than 1, decay factors are greater than 1

• Both growth and decay factors are greater than 1

• Both growth and decay factors are less than 1

Determine if the following represents percent growth or decay: 500(1.28)^3.

• Growth

• Decay

Determine the percent growth or decay for the following: 127(0.75)^8.

• 25% Growth

• 25% Decay