The first term of an arithmetic sequence is 123 the common difference is 12 and the sum is 1113 how many terms are in the series

You can use this formula of arthenatic series to find sum to get the number of term

sum = n:2 (2a + (n - 1) d)

n = number of tern = n

a = first term =

d = common difference

sum = 1113

you can find the number of series by putting in them