Answer:
Explained below.
Step-by-step explanation:
Consider the series is a set of first 6 natural numbers.
Sum of first <em>n</em> terms is:
Consider the series is an arithmetic sequence.
Sum of first <em>n</em> terms is:
Here<em>,</em>
<em>a</em> = first term
<em>d</em> = common difference
Consider the series is an geometric sequence.
Sum of first <em>n</em> terms is:
Here<em>,</em>
<em>a₁</em> = first term
<em>r</em> = common ratio