Identify Exponential Word Problems Versus Growth and Decay

A publishing industry report predicts that magazine subscriptions will drop by 10% each year. If this prediction is correct, then how many subscribers will a magazine with 98,000 subscribers have in 10 years? (Round to the nearest whole number if necessary).

• 34,170

• 16,348

• 7690

• 76,023

Lauren has $90 in a savings account. The interest rate is 5%, compounded annually. To the nearest cent, how much will she have in 2 years?

• $99.23

• $21.98

• $56.46

• $9.21

A cliff overlooking Oak Grove Lake is experiencing erosion, losing elevation at a rate of 5% every millennium. The cliff's current elevation is 1,200 meters. What will its elevation be in 6 millennia? (Round to the nearest whole number if necessary).

• 882

• 465

• 349

• 975

The mice population is 25,000 and is decreasing by 20% each year. What will be the mice population after 3 years?

• 12,800

• 15,777

• 102, 475

• 2,500

Your new computer cost $1500 but it depreciates in value by about 18% each year. How much will your computer be worth in 6 years? (Round to the nearest cent.)

• $456.01

• $556.98

• $778.22

• $332.63

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 initial quantity?

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

3.1(0.78)^t

Is the function growth or decay?

Check the box:

• Growth

• Decay