Exponential Functions Percent

A new savings account is opened with $400 and gains 3% every year. What is the exponential function?

• f(x)=400(1+3)^x

• f(x)=400(1-0.03)^x

• f(x)=400(1+0.03)^x

• f(x)=400(0.03)^x

A new savings account is opened with $1500 and gains 1.5% annual interest. What is the exponential function?

• f(x)=1500(1+1.5)^x

• f(x)=1500(1+0.015)^x

• f(x)=1500(1.00375)^x

• f(x)=1500(1.5)^x

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(1.08)^x

• y=15,000(0.92)^x

• y=15,000(0.08)^x

An adult takes 800 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%. How much ibuprofen is left after 6 hours? (hint: create equation first)

• 101

• 102

• 103

• 104

The expression 12(1.02)^t models the population of elephants in a wildlife refuge after t years since 1975.

What does the value 1.02 represent?

• The number of elephants was 102 in 1975.

• The number of elephants increases by 2% each year.

• The number of elephants increases by 102% each year.

• Two extra elephants join the population each year

The original value of a painting is $1400, and the value increases by 9% each year. Write a function to model this situation.

• y=1400(1.09)^x

• y=1.09(1400)^x

• y=1400(.91)^x

• y=1.09^x

Suppose a culture of bacteria begins with 5000 cells and dies by 30% each year. Write an equation that represents this situation.

• y=5000(1 - 0.30)^x

• y=30(5000)^x

• y=5000(1 + 0.30)^x

• y=5000x^x

The number of mosquitoes at the beginning of the summer was 4,000. The population of mosquitoes is expected to grow at a rate of 25% a month. How many mosquitoes will there be after 4 months?

• 9766

• 9006

• 9765

• 5433

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

• Growth

• Decay

• Linear

• None

The equation for this table is 

• y = 1(2^x)

• y = 1(12^x)

• y = 12x

• y = 12x + 1