Question

find the sum of the first 12 terms in the pattern below.

8, 11, 14, 17, ...

Answer 1

Thats an arithmetic series.
sum is given as
\(\huge S=(n/2)(2a+(n-1)d)\)
where a=1st term = 8 here
n=12 given
d= common difference = 3 here
just plug in values.