Congenial guests and plentiful supply of good things to eat and drink

Cogenial guest + Plentiful supply of good food --> successful party
(A+B -> C)
Since sylvia has more than enough to eat and drink + her guests are congenial, her dinner is certain to be a success
(A+D -> C) where D is a subset of B (sylvia's party has lots of food, but we know from the premise that's not what we need. We need a plentiful supply of good food)


The pattern of flawed reasoning exhibited by the argument above is most similar to that exhibited by which one of the following?

(A) The right ingredients, properly combined and baked in a reliable oven will always produce a well-baked cake. Since Emily has properly combined the right ingredients, her cake is certain to come out well if she bakes it in a reliable oven.
- Different logic. Do not see a subset of the premise

(B) If corn is baked with its husks on, the resulting dish will always be moist and sweet. Since George wishes to ensure that the corn he plans to serve is moist, he will be certain both to bake it and to leave its husks on.
- Different logic. Do not see a subset of the premise

(C) Making pie dough using ice water and thoroughly chilling the dough before rolling it out will ensure a flaky crust. Andrew thoroughly chilled his pie dough before rolling it out, so since he used ice water in making it, his pie is certain to have a flaky crust.
- Different logic. Do not see a subset of the premise

(D) If soup is made with a well-seasoned meat stock and fresh ingredients, it will always be welcome at dinner. Since to his meat stock Arnold added only very fresh ingredients, the resulting soup is certain to be welcome at dinner.
- Here's the correct answer. Arnold added fresh ingredients, but we know from the premise that's not sufficient. He needs well seasoned meat stock.

(E) Fresh greens, carefully washed and served with a light dressing, always produce a refreshing salad. Since Tisha has developed an exceptionally light dressing but never washes her fresh greens, no salad she serves will be a refreshing one.
- Different logic. Do not see a subset of the premise

D it is.

Clearly "D"

stem says: Congenial guests (X) + plentiful supply of food (Y) + good food (Z)------> good party (T)

Since X and Y are present then T will happen
Flaw ----> missing Z as the condition

"D" || the stem i.e. well seasoned meat (X) + fresh veggies (Y) ---> good dinner.....

Since Y is present then ----> good dinner.....same as stem


In "C" conclusion includes all ingredients required X,Y,Z....may be in different order, but that doesn't matter as per the stem

Original question:
Congenial guests(X) and plentiful supply of good things to eat and drink(Y) will ensure a successful dinner party(Z). Since Sylvia has prepared more than enough to eat and drink(Y') and her guests are all congenial people(X), her dinner party is certain to be a success(Z).
Reasoning flaw: If X and Y then Z, not if X and Y' then Z, although Y is similar to Y' and Y is a subset of Y'.

(D) If soup is made with a well-seasoned meat stock(Y) and fresh ingredients(X), it will always be welcome at dinner(Z). Since to his meat stock(Y') Arnold added only very fresh ingredients(X), the resulting soup is certain to be welcome at dinner(Z).
Reasoning flaw: If X and Y then Z, not if X and Y' then Z, although Y is similar to Y' and Y is a subset of Y'.

This is why D is the exact answer.

is the "good things" and the "well-seasoned" the only reason why we choose D?

I think these words are not the reason to come to D.

Congenial guests and plentiful supply of good things to eat and drink will ensure a successful dinner party. Since Sylvia has prepared more than enough to eat and drink and her guests are all congenial people, her dinner party is certain to be a success.

The logic here is:

If A (Congenial guests) and B (plentiful supply of good things to eat and drink) then C (a successful dinner party)
The flaw is: If A and D (more than enough to eat and drink) then C

B (plentiful supply of good things to eat and drink) is not the same as D (more than enough to eat and drink).
The flaw is lack of B to come to C.


(A) The right ingredients, properly combined and baked in a reliable oven will always produce a well-baked cake. Since Emily has properly combined the right ingredients, her cake is certain to come out well if she bakes it in a reliable oven.
There is no flaw in this sentence.
Logic is: If A (properly combined the right ingredients) and B (bake in a reliable oven) then C (produce a well-baked cake)


(B) If corn is baked with its husks on, the resulting dish will always be moist and sweet. Since George wishes to ensure that the corn he plans to serve is moist, he will be certain both to bake it and to leave its husks on.
There is no flaw in this sentence.
Logic: If A (corn is baked) and B (leave corn with its husks on) then C (moist and sweet)

(C) Making pie dough using ice water and thoroughly chilling the dough before rolling it out will ensure a flaky crust. Andrew thoroughly chilled his pie dough before rolling it out, so since he used ice water in making it, his pie is certain to have a flaky crust.
Also, there is no flaw here
Logic: if A (using ice water) and B (thoroughly chilling the dough before rolling out) then C (a flaky crust)

Andrew did B, also he had did A (so since he used ice water in making it), so the result is certain C.


(D) If soup is made with a well-seasoned meat stock and fresh ingredients, it will always be welcome at dinner. Since to his meat stock Arnold added only very fresh ingredients, the resulting soup is certain to be welcome at dinner.
Correct one.
Logic: If A (soup is made with a well-seasoned meat stock) and B (soup is made with fresh ingredients) then C (soup will be welcome at dinner).
Arnold did only B, he can't come to C. There is no A, the same flaw as the question.

(E) Fresh greens, carefully washed and served with a light dressing, always produce a refreshing salad. Since Tisha has developed an exceptionally light dressing but never washes her fresh greens, no salad she serves will be a refreshing one.
There is no flaw here.
Logic: If A (carefully washed fresh greens) and B (served with a light dressing) then C (produce a refreshing salad)
Tisha did B but A so won't come to C.

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