Try a Sample Logical Reasoning Question: Paradox

Test J, Section 3, Question 2 - Paradox

After replacing his old gas water heater with a new, pilotless, gas water heater that is rated as highly efficient, Jimmy’s gas bills increased.

Each of the following, if true, contributes to an explanation of the increase mentioned above EXCEPT:


The new water heater uses a smaller percentage of the gas used by Jimmy’s household than did the old one.


Shortly after the new water heater was installed, Jimmy’s uncle came to live with him, doubling the size of the household.


After having done his laundry at a laundromat, Jimmy bought and started using a gas dryer when he replaced his water heater.


Jimmy’s utility company raised the rates for gas consumption following installation of the new water heater.


Unusually cold weather following installation of the new water heater resulted in heavy gas usage.

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View Explanation

This argument presents a “paradox”—that is, a puzzling set of circumstances in need of an explanation.

Why the hell would Jimmy's gas bills go up after replacing his old gas water heater with a new, highly efficient one?

The correct answer will provide a satisfying explanation to that mystery.

Before looking at the answer choices, I might come up with a couple ideas. What if Jimmy's all like “I have this new efficient water heater, so now I'm going to take 45 minute showers twice a day?” Or what if the new water heater was installed incorrectly, so that it heats water to 1,000 degrees and instantly dumps it down the sewer line, 24 hours per day?

Either of these scenarios, if true, would explain the paradox. But there could be a thousand other similarly satisfying explanations.

A. This does nothing to explain why Jimmy's total bill went up. If anything, this makes it harder to understand. Since it's an EXCEPT question, this is probably the answer. We'll end up picking this, as long as B, C, D, and E all provide satisfying explanations to the paradox.

B. Yep, perfect explanation. The new, efficient water heater might be quite a bit better than the old one. But if Jimmy's uncle moved in, there could be a hundred different ways that Jimmy's gas bill went up. Maybe Jimmy's uncle takes 10 showers a day. Maybe Jimmy's uncle leaves the thermostat on 85 degrees with all the windows open. Maybe he leaves the kitchen stove burners on high without lighting them, attempting to get high off the gas fumes. This is an excellent explanation, so it's not the answer to this EXCEPT question.

C. Another good explanation. I don't care how efficient the new hot water heater is—if you start adding, and using, other gas appliances, your total bill could easily go up.

D. Gas prices went up? That's another good explanation.

E. Temperatures dropped, requiring increased gas for heating? That's yet another good explanation.

When you read the passage, you should have been scratching your head. B, C, D, and E all provide satisfying explanations to the paradox, so they're not the answer. The correct answer here is A, because it's the only one that doesn't provide a satisfying explanation.

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