Summation Notation, Geometric and Arithmetic Series

Find the sum of the first 15 terms in a geometric series with the first term 81, 920 and the ratio 1/2.

• 32/3

• 5

• 18

• 1589/3

Find the sum of the first 20 terms in a geometric series with the first term 9 and the common ratio -1.

• -20

• 20

• 15

• 415/2

Find the sum of the following series

2+4/3+8/9+16/27+ ...

• So sum

• 6

• -6

Expand the summation.

• -1800

• -1818

• -1825

• -1795

Expand and simplify if possible.

• 
• 
• 
• 

Write the expression in sigma notation

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• 
• 
• 

Evaluate to get (a)   .

• 290

• 278

• 250

• 295

What is the 67^th term of the following arithmetic sequence.

13, 22, 31, 40, ...

• -445

• 67

• 625

• 607

Which of the following is the correct formula in finding the nth term of an arithmetic sequence?

• a_n = a₁ + (n - 1)d

• a_n = a₁ + (n + 1)d

• a_n = a₁ - (n - 1)d

• a_n = a₁ +- (n + 1)d

What type of series is
32 + 16 + 8 + 4 + 2 + 1

• Finite Arithmetic

• Finite Geometric

• Infinite Arithmetic

• Infinite Geometric