Sum an arithmetic series and find its length

Question 1

An arithmetic series has 9 terms. The first term is 22 and the last term is −2. Find the sum.

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Question 2

The series 3 + 8 + 13 + … has a sum of 65. How many terms are there?

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Question 3

A theatre's first row has 29 seats and each row has 1 more than the row in front. There are 20 rows. How many seats are there altogether?

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Question 4

An arithmetic series has 40 terms. The first term is 10 and the last term is 127. Find the sum.

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Question 5

The series 8 + 13 + 18 + … has a sum of 1007. How many terms are there?

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Question 6

A theatre's first row has 17 seats and each row has 4 more than the row in front. There are 18 rows. How many seats are there altogether?

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Question 7

An arithmetic series has 36 terms. The first term is 8 and the last term is 218. Find the sum.

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Question 8

The series 10 + 15 + 20 + … has a sum of 385. How many terms are there?

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Question 9

A theatre's first row has 25 seats and each row has 1 more than the row in front. There are 11 rows. How many seats are there altogether?

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Question 10

An arithmetic series has 17 terms. The first term is 14 and the last term is 30. Find the sum.

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Question 11

The series 9 + 10 + 11 + … has a sum of 135. How many terms are there?

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Question 12

A theatre's first row has 17 seats and each row has 1 more than the row in front. There are 10 rows. How many seats are there altogether?

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Question 13

An arithmetic series has 31 terms. The first term is 30 and the last term is 210. Find the sum.

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Question 14

The series 7 + 11 + 15 + … has a sum of 297. How many terms are there?

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Question 15

A theatre's first row has 17 seats and each row has 4 more than the row in front. There are 24 rows. How many seats are there altogether?

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Question 16

An arithmetic series has 22 terms. The first term is 1 and the last term is 85. Find the sum.

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