A 500-gallon cistern is filled to half its capacity with water. At what rate, in gallons per minute, is the amount of water in the cistern increasing if both the inlet pipe and outlet pipe are open? (1) The inlet pipe pumps water into the cistern at a rate of 7 gallons per 30 seconds. (2) The outlet pipe pumps water out of the cistern at the rate of 12 gallons every 1 minute 30 seconds.

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.