exponential growth/decay & compound interest

Middletown High School has student elections every year. Lately, the school has seen a 5% decrease in voting from election to election. If 910 students voted this year, how many will be expected to vote 8 years from now? (Round to the nearest whole number if necessary).

• 604

• 777

• 29

• 198

More and more people are purchasing food from farmers' markets. As a consequence, a market researcher predicts that the number of farmers' markets will increase by 15% each year. If there are 6,200 farmers' markets this year, how many will there be in 10 years? (Round to the nearest whole number if necessary).

• 25,082

• 12,937

• 62,000

• 43,511

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

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

Thanks to its environmental initiatives, Silvergrove has cut its annual CO2 emissions by 5%. This year, the town produced 290,000 metric tons of emissions. If the downward trend continues, how much CO2 will be produced 7 years from now? (Round to the nearest whole number if necessary).

• 202,518

• 135,792

• 78,376

• 20,658

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

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

In the formula y=a(1+r)^t, what does the t represent?

• growth rate

• time

• initial amount

• text

In the formula y=a(1+r)^t, what does the r represent?

• growth rate

• time

• initial amount

• rounding