Practice Sum Of The First 𝑛 Terms (finite Geometric Series) (3)

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6 sample questions

Question 1.
Find the sum of the first 3 terms of the sequence: 1, 3, 9.
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Use the sum formula and identify a and r.
Question 2.
What is the first term in the series if a = 4 and r = 2?
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Recall that 'a' represents the first term.
3Question 3.
What is the formula for the sum of the first n terms of a geometric series?
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Remember the condition under which this formula applies.
4Question 4.
True or False: The common ratio can equal 1 for the finite series sum formula to work.
- True
- False
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Think about what happens to the formula when r is 1.
Question 5.
An investment of $500 grows at an annual interest rate of 7%. Calculate how much the investment will be worth after 10 years.
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Use the geometric growth formula for compound interest.
Question 6.
A bacterial culture grows threefold every hour, starting with 50 bacteria. How many will there be after 6 hours?
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This relates to the geometric series where r = 3 and n = 6.

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