Geometric Sequences and Exponential Growth and Decay

Which of the following graphs could be modelled using a geometric sequence?

• A

• B

• C

• D

The fourth, fifth and sixth terms of a geometric sequence are 7.5, 3.75 and 1.875 respectively. The sum of the first and second terms in the geometric sequence is:

• 15

• 30

• 45

• 90

A scientist observed that the population of a specific bird species is decreasing by 17% each year and that at the beginning of 2016, there were 483 birds. Predict the number of birds remaining at the beginning

of 2021.

Use the recursive rule 𝑡_n+1 = 0.65𝑡_n, t₁ = 120 to complete the following.

Calculate the percentage by which each term decreases

Use the recursive rule 𝑡_n+1 = 0.65𝑡_n, t₁ = 120 to complete the following.

Calculate the fourth term rounded to the nearest whole number.

P2 BONUS QUESTION: t₃ = 90, t₅ = 57.6. What is the first term (round answer to nearest whole number)?