Exponential Growth or Decay Word Problems

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

• final amount

• time

• original amount

• rate of growth

North Dakota has recently had the fastest growing population out of all 50 states. On Jan 1, 2013, the population of North Dakota was 700,000 people. North Dakota’s population has been growing by 5% per year. Express North Dakota’s population, N, in terms of years since 2013, t. Check the BEST answer:

• N=700,000(1.05)t

• N=700,000(1.5)t

• N=700,000(1-0.05)^t

• N=700,000(0.95)^t

An air freshener starts with 30 grams of fluid, and the amount of fluid decreases by 12% per day. Express the amount of grams of freshener, Q, that remains, t, days after it has begun being used.

Check the BEST answer: (HINT: that means simplify what is in the parenthesis)

• Q=30(1+0.12)^t

• Q=30(1-0.12)^t

• Q=30(0.88)^t

• Q=12(1.30)^t

What is the growth rate?

Write as a percent!

P = 8(1.23)^t

Is the function growth or decay?

Check the box:

• Growth

• Decay

What is the initial quantity?

What is the DECAY rate? Write as a percent! CAREFUL!!!

You start an account with $500 and an interest rate of 6% compounded yearly. How much is in the account after 3 years?

Round to the nearest cent. (two decimal places)

From 2000 - 2010 a city had a 2.5% annual decrease in population. If the city had 2,950,000 people in 2000, determine the city’s population in 2008.

Round to the nearest..... (these are people)... so whole number!

You buy a car for $8000 that depreciates at a rate of 11% a year. How much is the car worth after 5 years?

Round to the nearest cent. (two decimal places)