PCCP PRACTICE TEST 6

The function $y=7\left(\frac{4}{5}\right)^{-x}$  represents exponential growth or decay?

• Exponential Growth

• Exponential Decay

The function $y=7\left(\frac{5}{4}\right)^{-x}$  represents exponential growth or decay?

• Exponential Growth

• Exponential Decay

Write an equation that models the following situation:

Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 13% a week.

• y=6(0.13)^x

• y=6(1.13)^x

• y=6(0.87)^x

• y=6(13)^x

Identify the y-intercept: $f\left(x\right)=13\left(.27\right)^x$  

• (.27)^x

• .27

• 13

• 3.51

The population of Winnemucca, Nevada, can be modeled by P=6191(1.04)^t where t is the number of years since 1990. What percent did the population increase each year?

• 4%

• 0.4%

• 40%

• 400%

An adult takes 400 mg of ibuprofen. Each hour, the amount of ibuprofen in the person’s system decreases by about 29%.

What is the decay rate for this problem?

• 1.29

• .71

• .29

• 1.71

You bought a Boston Whaler in 2004 for $12,500. The boat's value depreciates by 7% a year. How much is the boat worth in 2012?

• $11625
• $6994.77
• $21,477
• $875

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? 

• 101
• 102
• 103
• 104

Is the pictured graph exponential growth or decay?

• Exponential Growth

• Exponential Decay

Write an equation that models the following situation:

The current student count at John Jay is 6500, it is expected to grow at a rate of 14% next year.

• y= 6500(1.14)^x

• y= 6500(0.86)^x

• y= 6500(14)^x

• y= 14(6500)^x