Mastering Geometric Series: Identify and Calculate Ratios

A car's value depreciates by 20% each year. If the car is worth $20,000 now, what will its value be after 3 years? Identify the geometric series and calculate the common ratio.

• 16000

• 10240

• 12000

• 8000

A bacteria culture doubles in size every hour. If you start with 500 bacteria, how many will there be after 5 hours? Identify the geometric series and calculate the common ratio.

• 16000

• 1000

• 8000

• 32000

A bank offers a savings account that pays 5% interest compounded annually. If you deposit $1,000, how much will you have after 4 years? Identify the geometric series and calculate the common ratio.

• 1215.51

• 1500.00

• 1100.00

• 1300.00

A video game character earns 100 points in the first level and then earns 150 points in the second level, increasing by 50 points each time. Is this a geometric series? If so, what is the common ratio?

• No, this is not a geometric series.

• Yes, this is a geometric series with a common ratio of 50.

• Yes, this is a geometric series with a common ratio of 1.5.

• No, this is a geometric series with a common ratio of 100.

A tree grows 1.5 times its height each year. If the tree is 2 meters tall now, how tall will it be after 4 years? Identify the geometric series and calculate the common ratio.

• 12.75 meters

• 10.125 meters

• 8.5 meters

• 6.0 meters

A family plans to save money for a vacation. They save $200 in the first month and increase their savings by 10% each month. How much will they save in the 6th month? Identify the geometric series and calculate the common ratio.

• 322.10

• 250.00

• 300.00

• 400.00

A cell phone plan offers a discount of 15% on the monthly fee each year. If the initial fee is $60, what will the fee be after 2 years? Identify the geometric series and calculate the common ratio.

• 45.00

• 43.35

• 36.00

• 50.00

A company’s profit increases by 25% each quarter. If the profit in the first quarter is $10,000, what will it be in the third quarter? Identify the geometric series and calculate the common ratio.

• $12,500

• $18,750

• $20,000

• $15,625

A plant grows 3 inches in the first month and then grows 1.5 times that amount each subsequent month. How much will it grow in the fourth month? Identify the geometric series and calculate the common ratio.

• 10.125 inches

• 8.5 inches

• 12 inches

• 6.75 inches

A subscription service charges $10 for the first month and increases the fee by 20% each month. What will the fee be in the fifth month? Identify the geometric series and calculate the common ratio.

• $30.00

• $25.00

• $20.74

• $15.00