#25 - The more demand there is for something, the easier it

[Overthinker99]

Here’s another take on the reasoning behind this question…aside from the crucial “part to whole” assumption/flaw. The stims premise says that “because there is less demand, the junkyards do not buy it.” All that provides us is the necessary condition of our general statement, which is that “harder to sell→ less demand (contrapositive of ” that more demand→easier to sell”). Satisfying our necessary is not enough to tell us the sufficient is true–that the car will be harder to sell-- which is our conclusion.

In that sense what we need is both a sufficient and necessary assumption: that “less demand” →”harder to sell.” That is exactly what “E” gives us: demand is a sufficient indicator of salability.

D is incorrect not only because it does not bridge the gap, but because its negation would merely be that "lack of demand would be offset by lack of supply." This would strengthen the assumption more than weaken it, as we’d be left with a net-zero difference while we know that newer cars are easier to sell.

[kristinajohnson@berkeley.edu]

The more demand there is for something, the easier it is to sell. Any junkyard will buy a used car that is less than ten years old, because the parts can easily be resold. However, because there is little demand for car parts that are ten years old or older, junkyards tend not to buy those cars. Thus, used cars that are less than ten years old are generally easier to sell than are cars that are ten years old or older.

(A) The salability of something is not influenced by any factors other than the level of demand for it.

No. “The more demand there is for something, the easier it is to sell”

(B) All used cars that are ten years old or older are sold to junkyards.

No. “junkyards tend not to buy those cars”

(C) In general, the older something is, the more difficult it is to sell.

No. “because there is little demand for car parts that are ten years old or older, junkyards tend not to buy those cars.” Too broad, maybe if it was “the older something is, the more difficult it is to sell” ITS PARTS

(D) When determining the selling price of cars less than ten years old, the lack of demand would not be offset by a lack of supply.

No. This is not supported by the stimulus, and “the lack of demand” is about cars that are ten years old or older. Also, lack of demand for cars would not balance lack of supply of cars? Can I even bring the supply side into this problem or is it out of scope?

HERE'S ALL THE TROUBLE

(E) The salability of cars that are ten years old or older is largely a function of the level of demand for their parts.

The salability of cars that are ten years old or older is NOT largely a function of the level of demand for their parts.

Rephrasing negated (E), cars that sell, that are ten years old or older don’t sell because of a demand for their parts

Premise: “there is little demand for car parts that are ten years old or older”

Conclusion: “used cars that are less than ten years old are generally easier to sell than are cars that are ten years old or older”

Is this saying the entire car that's less than ten years old is easier to sell than the entire car that’s ten years old or older?

Answer choice (E) could be negated or not and both seem to help? How does the assumption negation technique weaken this problem? Old cars aren’t selling very much and old car parts aren’t selling very much???

The stimulus says "there is little demand for car parts that are ten years old or older," and "used cars that are less than ten years old are generally easier to sell than are cars that are ten years old or older” this is more in line with an answer choice that says "The salability of cars that are ten years old or older is largely a function of the level of demand for" THE ENTIRE CAR? The stimulus explicitly says something about the low demand for old car PARTS and only says less old entire cars are easier to sell than OLD ENTIRE CARS. The assumption seems more in line with my made up, better answer (F), let’s call it???

Dear LSAC, here’s what you should use next time in place of (E): The salability of cars that are ten years old or older is largely a function of the level of demand for the entire car. You’re welcome.

[Jeff Wren]

Hi Kristina,

You asked:

Is this [the conclusion] saying the entire car that's less than ten years old is easier to sell than the entire car that’s ten years old or older?

Yes, and that shift from junkyards buying used cars for their parts (which is discussed in the premises) to selling whole used cars more generally (which is discussed in the conclusion), such as selling to people who want to buy the used cars to actually drive them rather than just use them for their parts, is the huge logical gap/flaw in the argument and the key to solving this question.

The basic gist of this argument is that, because used cars that are less than ten years old are easier to sell to junkyards than used cars that are ten years or older, used cars that are less than ten years old must be easier to sell in general/overall (i.e. even when not selling them to junkyards) than used cars that are ten years or older.

Because there is a logical gap in this argument, you should be looking for a supporter assumption that closes the logical gap in the argument by linking the new information in the conclusion (selling the used cars in general/overall) to the premises.

Answer E does this. The argument is assuming that used cars that are ten years or older are mainly just sold for their parts, which is why the fact that junkyards don't really want to buy these older cars indicates that they are usually harder to sell in general. In other words, if the junkyards aren't interested in buying your old car, you're out of luck because nobody else would want to buy your old car to use for transportation.

The negation of Answer E would indicate that how likely used cars that are ten years or older sell is not largely based on the demand for their parts, which would directly attack the conclusion. In other words, who cares if junkyards don't want to buy these cars for their parts as long as somebody could sell them to another buyer who wants to actually use the car for transportation.

Your suggested answer:

The salability of cars that are ten years old or older is largely a function of the level of demand for the entire car.

is actually the opposite of what the argument is assuming. As discussed above, if this were true, then the fact that junkyards don't want to buy these older cars for their parts would not support the conclusion that these older cars are harder to sell in general, because the value of these cars wouldnot simply be for their parts, which is what the argument is assuming.