Exponential Word Problems

You have 30,016 grams of radioactive kind of rubidium. How much will be left after 54 minutes if its half-life is 18 minutes?

• 15,008 grams.

• 7,504 grams

• 3,752 grams.

• 1,876 grams.

A city doubles its size every 64 years. If the population is currently 225,000, what will the population be in 128 years?

• The population will be 225,000.

• The population will be 450,000.

• The population will be 900,000.

• The population will be 1,800,000.

Ash has $8,000 in a savings account. The interest rate is 3% compounded once a year. How much will he have in his account in 4 years? Round to the nearest hundredth.

• $9,004.07

• $2,2848.80

• $9,011.94

• $8,242.71

A sailboat that costs $5,950 decreases in value by 11% per year. How much will the boat be worth after 6 years?

• $5,884.00

• $5,178.97

• $2,992.96

• $2,957.04

The value of a car purchased for $20,000 decreases at a rate of 12% per year. What will be the value of the car after 3 years?

• $12,800.00

• $13,629.44

• $17,600.00

• $28,098.56

The population of Pallet Town increases by 15% every year. If there are currently 190,000 people living there, what will be the population in 13 years?

If necessary, round your answer to the nearest whole number.

• 4 people

• 22,972 people

• 1,169,030 people

• 1,188,311 people

Due to its weakening steel industry, Canalave Town has been experiencing a population decline of 10% every year. The current population is 74,000 people. Assuming the trend continues, which equation projects the population in x years?

• y = 74,000 (0.10)^x

• y = 74,000 (0.90)^x

• y = 74,000 (1.10)^x

• y = 74,000 (1.90)^x

The number of research papers in Professor Sycamore area of expertise has been increasing by 5% every year. Given that 30,010 research papers were published this year. Assuming the trend continues, which equation projects the amount of research papers published in x years?

• y = 30,010 (.05)^x

• y = 30,010 (1.05)^x

• y = 30,010 (.95)^x

• y = 30,010 (5)^x

A newly launched clothing line is rapidly increasing in popularity. Every month, 20% more items of clothing are sold. If 89,090 items were sold this month, how many will be sold in 9 months from now? If necessary, round your answer to nearest whole number.

• 74,278 items

• 11,957 items

• 319,226 items

• 459,685 items

Katy deposited $90 in a savings account earning 5% interest, compounded quarterly. Which of the following equations could represent the amount of money in her account yearly?

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