V03-14

Question

The popular belief that a snake's age can be determined by counting the number of layers of scales on its body is generally true. However, to help regulate its internal temperature, the outermost layers of scales of the Black Mamba snake often peel away when the temperature exceeds 120 degrees Fahrenheit, leaving the snake with fewer layers of scales than it would otherwise have. So only if the temperature in the Black Mamba's environment never exceeds 120 degrees Fahrenheit will its layers be a reliable measure of the snake's age.
 
Which of the following is an assumption on which the argument is based?

A. The growth of new layers of scales in a snake is not a function of levels of its basal metabolic rate.
B. Only the Black Mamba loses layers of scales because of excessive heat.
C. One day of temperatures above 120 degrees Fahrenheit will cause the Black Mamba snake to lose a layer of scales.
D. The layers of scales of all snakes are of uniform thickness.
E. The number of layers of scales that will be lost when the temperature exceeds 120 degrees Fahrenheit is not predictable.

Bunuel · Answer

Official Solution:

The popular belief that a snake's age can be determined by counting the number of layers of scales on its body is generally true. However, to help regulate its internal temperature, the outermost layers of scales of the Black Mamba snake often peel away when the temperature exceeds 120 degrees Fahrenheit, leaving the snake with fewer layers of scales than it would otherwise have. So only if the temperature in the Black Mamba's environment never exceeds 120 degrees Fahrenheit will its layers be a reliable measure of the snake's age.
 
Which of the following is an assumption on which the argument is based?

A. The growth of new layers of scales in a snake is not a function of levels of its basal metabolic rate.
B. Only the Black Mamba loses layers of scales because of excessive heat.
C. One day of temperatures above 120 degrees Fahrenheit will cause the Black Mamba snake to lose a layer of scales.
D. The layers of scales of all snakes are of uniform thickness.
E. The number of layers of scales that will be lost when the temperature exceeds 120 degrees Fahrenheit is not predictable.

The argument concludes that one will only be able to determine the age of a Black Mamba by counting its layers of scales if the temperature in the snake's environment never exceeds 120 degrees Fahrenheit. Argument makes this conclusion on the fact that the snake loses layers of scales when the temperature exceeds the level. However, if the number of layers of scales lost by a Black Mamba at high temperatures could be predicted, then it might be possible to determine the age of a snake even if the temperature exceeds 120 degrees. The argument actually assumes that it is not possible to predict the number of layers of scales lost when the temperature exceeds 120 degrees Fahrenheit.
 
A. The argument says nothing about basal metabolic rate. This answer choice is out of scope since it would require a number of other assumptions to make it relevant to the argument's conclusion.
 
B. Whether other snakes share this feature is irrelevant; the argument focuses only on the Black Mamba.
 
C. This choice says that one day of temperatures above 120 degrees = one ring lost. If this is true, then we could actually be able to predict the number of layers of scales lost (if we also know on how many days the temperature exceeded 120 degrees). This damages the author’s argument; therefore, it cannot be an assumption on which the author depends.
 
D. The thickness of the layers of scales is irrelevant.
 
 E. CORRECT.  The argument’s conclusion is that the layers of scales will be a reliable measure only if the temperature never exceeds 120 degrees. This is true only if there is no way to predict how many layers of scales would be lost when the temperature does exceed 120 degrees. (If it were possible to predict this, one might be able to assess the age of a snake using its layers of scales even if the temperature had exceeded 120 degrees.)

Answer: E

puto · Answer

Para states that : the outermost layers of scales of the Black Mamba snake often peel away when the temperature exceeds 120 degrees Fahrenheit.

Outermost layer could only be one at a time

How is E correct then?

sayantanc2k · Answer

Not necessarily - 3 outermost layers imply the top 3 layers. If singular "layer" is used then what you are saying is valid.

puto · Answer

Thanks...

14razy · Answer

I think people should be very careful when they want to rule out an answer choice because they believer it's "outside the scope". In a strengthen/weaken question, answer choices are taken to be true/given and allowed to talk about things that have not been said. I mean, otherwise, what you think an assumption is? So why people simply say the answer A is " outside the scope"? Bunuel, could you please elaborate on this?

sayantanc2k · Answer

An assumption should link the premise with the conclusion. If an additional piece of information does not work as the link, then it is alright to say that the information is out of scope. There is no problem with the OE given for option A.

14razy · Answer

Sayantanc2k, I think what you mean is if the answer choice A were to read as "the snake's age is not a function of base metabolic rate "(it's a funny assumption), then A would become appealing because now that it rules out a possible alternate cause/determinant of a snake's age. The reason I'm sweating "outside the scope" is that I want to learn to distinguish it from "ruling out an alternate explanation". In this particular question, "Only if" in the last sentence of the argument implies the argument/way a snake's age is calculated won't apply if the temperature goes above 120 degree. In that sense, yes, the argument seems to limit the conclusion to a below 120 degree situation.

bpdulog · Answer

Hi,

My opinion is that C is the best answer here. The argument states that if temp NEVER exeeds 120 degrees, then age based on scales is accurate. However, it seems like if this temperature is exceeded for 1 day, 1 hour, etc. then all hope is lost to determine an accurate age.

OhsostudiousMJ · Answer

Hi,
The passage gives a general fact regarding snakes, but suddenly jumps to explain the specific exception, i.e., the black mamba, and this is what made me choose B. Any thoughts on this?

TIA.

oyin26 · Answer

I am not totally clear on why the answer is E. Even if the number of layers that will be lost when the temperature exceeds 120 degrees Fahrenheit is predictable, is the number of times the temperature exceeds 120 degrees Fahrenheit also predicatble? Option E does not address this.

Expert, please assist with an explanation.

Expert, please assist with an explanation.

KarishmaChauhan · Answer

Can you please elaborate choice E as I also eliminated it because even if it is possible to know how many scales it loses after it loses its outermost skin layers we wouldn't know how many times that snake faced temperature above 120 F and how many times it lost its skin during its lifetime before we want to caluculate its age, we still can't be sure hence this answer stays invalid. Or should we just assume that it loses only once even if it is not mentioned anywhere in the passage? Is it an official question? This was the first thought that came to my mind when I saw the explanation. Can someone please assist?

sarthak952 · Answer

I think this is a  high-quality  question and I agree with explanation.

adarq · Answer

I think this is a  high-quality  question and I don't agree with the explanation. The assumption talks about "snake's age" and refers the Black Mamba as an example. So it must assume that losing layers of scales because of excessive heat occurs only to Black Mamba for this to be a reliable measure on "snake's age". Why not answer choice B?

GKomoku · Answer

yes, please somebody explain why B exactly incorrect with more details?

GKomoku · Answer

why not B?

leepcoast · Answer

I think this is a  high-quality  question and I don't agree with the explanation. For me, option C also seems to be right. The passage says:
(i) that Black Mamba OFTEN peel away when temperature exceeds 120F (often, not always)
(ii) ONLY IF temperature NEVER exceeds 120F the layers will be a reliable measure of the snake's age.

But what if the Black Mamba needs to be exposed to 120F for a few days to have a layer peel away? So T can exceed 120F during the only a few hours of a day, and the layers will still be a reliable measure of snake's age. So option C "ONE DAY will cause the Black Mamba to lose a layer of scales" is an assumption in which the argument is based.

awaikar · Answer

I don’t quite agree with the solution. There is no mention of the length of time required for the temperature to be above 120F for the mamba to lose it's scales

shuklashikhar · Answer

I like the solution - it’s helpful.

Sushi_545 · Answer

HI  Bunuel ,

For choice C "One day of temperatures above 120 degrees Fahrenheit will cause the Black Mamba snake to lose a layer of scales." Argument states that "only if" the temprature in black mambas env never exceeds 120 degrees Fahrenheit will its layers be a reliable measure of the snake's age. 
here isnt C must be true because even if one day of temprature above 120 degrees Fahrenheit will "not" cause the Black Mamba snake to lose a layer of scales yhen its layer will not be a reliable way to predict its age. can you please clarify.

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