Given an arithmetic sequence of N terms in which the common difference between terms is 2, what is the value of N? (1) The first term is 18. (2) The last term is 70.

Data Sufficiency questions are exclusive to the GMAT.

Each Data Sufficiency question poses a question, followed by two statements. Your task is to evaluate the statements to determine at what point there is or is not sufficient information to answer the question.

Unlike the Problem Solving questions, you do not actually have to answer the question posed. Instead, you select one of five fixed answer choices that offer different options about the sufficiency of the information provided in the two statements.