Question

A theater has 41 seats in the first​ row, 44 seats in the second​ row, 47 seats in the third​ row, and so on. How many seats are there in row 15​?
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Part 1
There are
  
enter your response here seats in row 15.

Answers

GPT-4o mini
To find the number of seats in row 15, we can observe the pattern in the number of seats per row:

- Row 1: 41 seats
- Row 2: 44 seats
- Row 3: 47 seats

From this, we can see that each subsequent row increases by 3 seats. This indicates that the number of seats in each row forms an arithmetic sequence where:

- First term (Row 1): \( a_1 = 41 \)
- Common difference: \( d = 3 \)

The formula for the \( n \)-th term of an arithmetic sequence is given by:

\[
a_n = a_1 + (n-1) \cdot d
\]

Where:
- \( a_n \) is the number of seats in row \( n \)
- \( a_1 \) is the number of seats in the first row
- \( d \) is the common difference
- \( n \) is the row number

Plugging in the values for row 15:

\[
a_{15} = 41 + (15-1) \cdot 3
\]

Calculating it:

\[
a_{15} = 41 + 14 \cdot 3
\]
\[
a_{15} = 41 + 42
\]
\[
a_{15} = 83
\]

So, there are **83 seats** in row 15.

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