Mastering Geometric Sequences: Sums and Graphs for 8th Grade

A bacteria culture doubles in size every hour. If the initial size is 100 bacteria, how many bacteria will there be after 5 hours?

• 4000

• 1600

• 3200

• 2400

A car's value decreases by 20% each year. If the car is worth $15,000 now, what will its value be after 3 years?

• $12,000

• $10,000

• $5,000

• $7,680

A tree grows 1.5 times its height each year. If it is currently 2 meters tall, what will its height be after 4 years?

• 12.5 meters

• 5.0 meters

• 10.125 meters

• 8.0 meters

A savings account earns interest at a rate of 5% compounded annually. If you start with $1,000, how much will you have after 3 years?

• 1200.00

• 1300.75

• 1157.63

• 1100.50

A video game character earns 50 points in the first level and then doubles the points earned in each subsequent level. How many points will the character earn after 6 levels?

• 1024

• 3150

• 600

• 1500

A company’s profit increases by 10% each year. If the profit this year is $200,000, what will it be in 5 years?

• $400,000

• $250,000

• $322,102.50

• $280,000

A geometric sequence starts with 3 and has a common ratio of 4. What is the sum of the first 4 terms?

• 81

• 255

• 64

• 120

If a geometric sequence has a first term of 5 and a common ratio of 3, what is the 6th term of the sequence?

• 1215

• 243

• 729

• 405

Graph the first 5 terms of the geometric sequence where the first term is 2 and the common ratio is 3. What do you notice about the graph?

• The first five terms of the sequence are 2, 6, 18, 54, 162.

• The first five terms are 2, 5, 10, 20, 40.

• The first five terms are 1, 3, 9, 27, 81.

• The first five terms are 2, 4, 8, 16, 32.

A cell phone plan offers 1 GB of data in the first month and increases by a factor of 1.5 each month. How much data will be available in the 6th month?

• 3.5 GB

• 5 GB

• 7.59 GB

• 10 GB