AbeNeedsAnswers wrote:City council member: Demand for electricity has been increasing by 1.5 percent a year, and there simply is no more space to build additional power plants to meet future demand increases. We must therefore begin to curtail usage, which is why I propose passing ordinances requiring energy-conservation measures in all city departments.

The city council member's proposal assumes which of the following?

A. Existing power plants do not have capacity to handle all of the projected increase in demand for electricity.
B. No city departments have implemented energy-conservation measures voluntarily.
C. Passing ordinances designed to curtail electricity usage will not have negative economic consequences for the city.
D. Residential consumers are not responsible for the recent increases in demand for electricity.
E. City departments that successfully conserve energy will set a good example for residential and industrial consumers of electricity.

A

PREMISE: Electricity demands increase 1.5% per year
PREMISE: No space to build more power plants
CONCLUSION: We must use LESS electricity through ordinances

Strategy #1: Try to think of an assumption that's required for the conclusion to logically follow from the premises.
Notice that nothing is mentioned about how the power plants are handing the present demands.
After all, it could be the case that, to meet the present demands, the power plants need only operate at 5% capacity, in which case, it may not be necessary to implement energy-conservation measures.
As assumption is that the existing power plants are not able to handle increases in demand

Now look for YOUR answer among the answer choices . . . answer choice A seems similar to our assumption.

Answer: A

ASIDE: In many cases, you will be unable to identify a needed assumption. No problem.
This brings us to . . .

Strategy #2: NEGATE each answer choice. If the NEGATED assumption DESTROYS the conclusion, then that answer choice must be correct.
Why? If the negated assumption destroys the conclusion, we must need that assumption to be true.

A) Existing power plants DO have capacity to handle all of the projected increase in demand for electricity.
Does this negated statement DESTROY the conclusion that the city must use LESS electricity through ordinances?
YES!! It kills the conclusion.
If we have enough capacity to handle future demand, there's no NEED to use less power.

Answer: A

Cheers,
Brent