Correct Answer:
Second option
Solution:
The given sequence is:
2.2, 6.6, 11, ...
If we observe the sequence it is an Arithmetic Sequence as the difference between two consecutive terms is the same.
6.6 - 2.2 = 4.4
11 - 6.6 = 4.4
First we find the general term for this sequence.
[tex]a(n)= a_{1}+(n-1)d [/tex]
[tex] a_{1}= [/tex]first term = 2.2
d = 4.4
So,
[tex]a(n) = 2.2 +(n-1)*4.4 \\ \\
a(n) = 2.2 + 4.4n - 4.4 \\ \\
a(n) = 4.4n - 2.2[/tex]
This general term will be placed inside the summation sign with limits from 1 to 5 to give the sum of first 5 terms of the given sequence. So the correct answer is Second Option
