Question

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

Answer 1

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