Question

Find the next 2 terms in the Geometric sequence 20,30,45 ...

Answer 1

Answers:

The next two terms are 67.5 and 101.25 in that order.

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Explanation:

Divide the second term over the first to get 30/20 = 1.5

Divide the third term over the second term to get 45/30 = 1.5

The common ratio is 1.5, which means we multiply 1.5 by each term to get the next term

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fourth term = 1.5*(third term) = 1.5*45 = 67.5

fifth term = 1.5*(fourth term) = 1.5*67.5 = 101.25

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As a shortcut you can plug n = 4 and n = 5 into the function t(n) = 20*(1.5)^(n-1) to get the fourth and fifth terms respectively.