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.

"Surprising" Phenomenon
Why did Jimmy’s gas bills increase after replacing his old water heater with the new one?

Objective
The correct answer will be the only answer that doesn’t help explain the phenomenon of Jimmy’s gas bills going up after replacing his old water heater with his new one. The correct answer must give us information that doesn’t affect our understanding of the phenomenon or information that makes the phenomenon more difficult to explain.

A
The new water heater uses a smaller percentage of the gas used by Jimmy’s household than did the old one.
(A) doesn’t help explain why the new water heater is costing Jimmy more for gas. If the new water heater is using a smaller percentage of the house’s gas than the old water heater did, we’d expect Jimmy to spend less on gas for the new water heater.
B
Shortly after the new water heater was installed, Jimmy’s uncle came to live with him, doubling the size of the household.
The number of people using gas in the household doubling after installing the new water heater would likely lead to an increase in the amount Jimmy is spending on gas.
C
After having done his laundry at a laundromat, Jimmy bought and started using a gas dryer when he replaced his water heater.
If Jimmy started using a gas dryer in his home when he previously didn’t have a dryer, it could help explain why he’s now spending more on gas even though his new water heater is more gas-efficient than his old one.
D
Jimmy’s utility company raised the rates for gas consumption following installation of the new water heater.
Higher rates for gas could lead to Jimmy paying more for gas even if his new water heater is more gas-efficient than his old water heater.
E
Unusually cold weather following installation of the new water heater resulted in heavy gas usage.
If Jimmy had to use an unusually high amount of gas because of cold weather, it could have led to him spending more on gas for his new water heater even though it’s more gas-efficient than his old water heater.

4 comments

Carolyn: The artist Marc Quinn has displayed, behind a glass plate, biologically replicated fragments of Sir John Sulston’s DNA, calling it a “conceptual portrait” of Sulston. But to be a portrait, something must bear a recognizable resemblance to its subject.

Arnold: I disagree. Quinn’s conceptual portrait is a maximally realistic portrait, for it holds actual instructions according to which Sulston was created.

Speaker 1 Summary
Carolyn’s implicit conclusion is that the “portrait” of Sulston isn’t actually a portrait. This is because in order for something to be a portrait of a thing, it must have a recognizable resemblance to that thing. Sulston’s “portrait” is just fragments of DNA, which Carolyn thinks does not resemble Sulston.

Speaker 2 Summary
Arnold believes the “portrait” is a portrait. This is because it contains the genetic instructions according to which Sulston was created.

Objective
We’re looking for a disagreement. The speakers disagree on whether the “portrait” is really a portrait. Carolyn thinks it isn’t. Arnold thinks it is.

A
should be considered to be art
Neither speaker has an opinion. Nobody discusses what is or is not art, only what is or is not a portrait.
B
should be considered to be Quinn’s work
Neither speaker has an opinion. Nobody discusses whether the work is appropriately considered Quinn’s.
C
bears a recognizable resemblance to Sulston
Arnold has no opinion. He doesn’t suggest that the portrait does or does not resemble Sulston. Arnold simply applies a different rule, unrelated to resemblance, for determining that something is a portrait.
D
contains instructions according to which Sulston was created
Carolyn has no opinion. She doesn’t speak to whether the DNA fragments contain instructions according to which Sulston was created.
E
is actually a portrait of Sulston
This is a point of disagreement. Carolyn’s implicit conclusion is that it’s not a portrait of Sulston. Arnold’s conclusion is that it is a portrait of Sulston.

10 comments

Many corporations have begun decorating their halls with motivational posters in hopes of boosting their employees’ motivation to work productively. However, almost all employees at these corporations are already motivated to work productively. So these corporations’ use of motivational posters is unlikely to achieve its intended purpose.

A
fails to consider whether corporations that do not currently use motivational posters would increase their employees’ motivation to work productively if they began using the posters

The author’s argument only addresses “these corporations’ use of motivational posters,” referring to the many corporations who have already begun hanging motivational posters. Whether any other corporations might benefit from the posters is irrelevant.

B
takes for granted that, with respect to their employees’ motivation to work productively, corporations that decorate their halls with motivational posters are representative of corporations in general

This is the cookie-cutter flaw of hasty generalization. The author doesn’t make this mistake. Her conclusion isn’t about corporations in general, it’s only about the corporations that decorate their halls with motivational posters.

C
fails to consider that even if motivational posters do not have one particular beneficial effect for corporations, they may have similar effects that are equally beneficial

Even if motivational posters do have other beneficial effects, this doesn’t impact the author’s argument. Her conclusion is simply that the posters are unlikely to achieve their intended purpose, which is to boost employees’ motivation to work productively.

D
does not adequately address the possibility that employee productivity is strongly affected by factors other than employees’ motivation to work productively

The author’s argument is only about the posters’ effect on employees’ motivation to work productively. Whether their productivity is also affected by other factors is irrelevant.

E
fails to consider that even if employees are already motivated to work productively, motivational posters may increase that motivation

The author assumes that the posters won’t boost motivation, just because the employees at these corporations are already motivated. She fails to consider that the posters could increase employees’ motivation even more.


8 comments

A year ago the government reduced the highway speed limit, and in the year since, there have been significantly fewer highway fatalities than there were in the previous year. Therefore, speed limit reduction can reduce traffic fatalities.

Summarize Argument: Phenomenon-Hypothesis

The author concludes that a speed limit reduction can reduce traffic fatalities. This is based on the fact that a year ago, the government reduced the highway speed limit, and in the year since that reduction, there have been fewer highway deaths than there were in the previous year.

Identify and Describe Flaw

The author assumes that the reduction in highway speed limit caused the decrease in highway fatalities. This overlooks the possibility that there are other explanations for the decrease in highway fatalities in the year following the speed limit reduction.

A
highway traffic has not increased over the past year

The negation of (A) doesn’t undermine the argument. If traffic has increased over the past year, that might strengthen the argument, because we’d expect to see more fatalities. Since the negation doesn’t hurt the argument, the author doesn’t have to assume (A).

B
the majority of drivers obeyed the new speed limit

The author doesn’t have to assume that most drivers obeyed the speed limit, because a speed limit reduction can still affect driving behavior even if most people don’t follow the speed limit. For example, the new limit can cause people to drive slower.

C
there is a relation between driving speed and the number of automobile accidents

The author’s conclusion concerns the number of highway deaths. This doesn’t commit the author to any belief about the number of accidents, which is different from the number of deaths.

D
the new speed limit was more strictly enforced than the old

If anything, the author assumes that the new speed limit was not more strictly enforced. More strict enforcement could have been an alternate explanation for the decline in fatalities. So the author assumes this didn’t happen, not that it did happen.

E
the number of traffic fatalities the year before the new speed limit was introduced was not abnormally high

This must be assumed because if the number of fatalities the year before the new limit was abnormally high, then that suggests the decrease in fatalities after the speed limit might just be a coincidence. It might be a return to the normal fatality rate.


106 comments