A series is the sum of the terms of a sequence.
Below we have a representation of theatre seating. The 1st row has just 3 seats, while the 8th row has 10 seats.
How many people can sit in the first five rows? To find the answer, we simply add the first five rows:
3 + 4 + 5 + 6 + 7 = 25 people
This is an arithmetic series.
|Sum of an Arithmetic Series|
The sum for the first n terms of an arithmetic series is given by the equation:
where n is the number of terms, and a is each individual term.
So, for our example the total sum for the first 7 rows is equal to: