Question

What is the sum of the arithmetic sequence 6, 14, 22 …, if there are 26 terms? 2,754 2,756 2,758 2,760 -

Answer 1

This is the concept of sequences and series;
The sum of arithmetic series is given by:
Sn=n/2(2a+(n-1)d)
n=number of terms
a=1st term
d=common difference
From our sequence;
a=6, d=8, n=26
hence;
Sn=26/2(2*6+(26-1)8)
Sn=13(12+25*8)
Sn=13(12+200)
Sn=13(212)
Sn=2,756
The answer is 2,756