Sequencing problem - Is it possible to solve this problem with the given information
I have a sequencing problem that I cannot find a way to solve using the three major formulas for finding sequencing elements.
The difference between terms is given (1/2). The sum of the terms is minus 105/2, and the last term is also given (0).
However, neither the first term nor the number of terms is given.
I cannot find a way to solve such a problem. All of the formulas seem to require both the number and the first term and/or the last term.
The answers given are: Minus 7 for the first term, and 15 as the number of terms.
If this is solvable, I would very much appreciate the formula sequence.
If not, I would like to know that as well.
Thanks so much.