servings

[anant03]

Please advise.

[Brent@GMATPrepNow]

Malik's recipe for 4 servings of a certain dish requires 1 1/2 cups of pasta. According to this recipe, what is the number of cups pasta that Malik will use the next time he prepares this dish?

1) The next time he prepare this dish, Malik will make half as many servings as he did the last time he prepared the dish

2) Malik used 6 cups of pasta the last time he prepared this dish

Target question: How many cups of pasta will Malik use the next time he prepares this dish?

Given: 4 servings of a certain dish requires 1 1/2 cups of pasta.
So, if we can determine the NUMBER OF DISH SERVINGS Malik prepares, we can determine how much past is required.

Statement 1: The next time he prepare this dish, Malik will make half as many servings as he did the last time he prepared the dish
We have no idea how many servings Malik made last time. So, we cannot determine the number of servings he'll make next time.
So, statement 1 is NOT SUFFICIENT

Statement 2: Malik used 6 cups of pasta the last time he prepared this dish
This information does not help us determine how much pasta he'll need NEXT TIME.
So, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 2: Malik used 6 cups of pasta the last time
Statement 1: Next time, Malik will make half as many servings as he did the last time. If we makes half as many servings, Malik will need half as much pasta as he needed last time.
So, Malik will need 3 cups of pasta next time
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer = C

Cheers,
Brent

[[email protected]]

Hi anant03,

There's an aspect to this question that many Test Takers mis-handle: In this type of question, a "recipe" is just a set of cooking instructions - it does NOT tell you how many servings a person actually chose to make. In this way, answering this DS question is more about logical thinking than about math 'skills.'

According to this recipe, we're told that 4 servings requires 1.5 cups of pasta, but we DO NOT know how many servings Malik made (or chooses to make). We're asked how much pasta Malik will need the NEXT TIME he prepares the dish.

Fact 1 refers to "half" the servings he made the last time, but we don't know how many servings he made last time. Maybe he made 4 servings, maybe he made 8 or 12 or 16, etc. so Fact 1 is INSUFFICIENT. Fact 2 is also INSUFFICIENT. Combined though, we know how many servings Malik made "last time" and that he will make half as much as the next time.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

[Max@Math Revolution]

Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and equations ensures a solution.


Malik's recipe for 4 sercings of a certain dish requires 3/2 cups of pasta. According to this recipe, what is the number of cups of pasta that Malik will use the next time he prepares this dish?
1) The next time he prepares this dish, Malik will make half as many servings as he did the last time he prepared the dish
2) Malik used 6 cups of pasta the last time he prepared this dish

In the original condition there are 2 variables (dish from last time:x, dish for next tme:y) and thus we need 2 equations to match the number of variables and equations. Since there is 1 each in 1) and 2), C is likely the answer.

Using both 1) & 2) together, y=x/2 and the number of dish: number of pasta=1:3/2=2:3, therefore 2:3=x:6, 3x=12, x=4 and y=4/2=2. Therefore the conditions are sufficient. The answer is C.

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[Mo2men]

Hi anant03,

There's an aspect to this question that many Test Takers mis-handle: In this type of question, a "recipe" is just a set of cooking instructions - it does NOT tell you how many servings a person actually chose to make. In this way, answering this DS question is more about logical thinking than about math 'skills.'

According to this recipe, we're told that 4 servings requires 1.5 cups of pasta, but we DO NOT know how many servings Malik made (or chooses to make). We're asked how much pasta Malik will need the NEXT TIME he prepares the dish.

Fact 1 refers to "half" the servings he made the last time, but we don't know how many servings he made last time. Maybe he made 4 servings, maybe he made 8 or 12 or 16, etc. so Fact 1 is INSUFFICIENT. Fact 2 is also INSUFFICIENT. Combined though, we know how many servings Malik made "last time" and that he will make half as much as the next time.

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

Dear Rich,
I really find hard times to understand the question.

I did the follows:

Given recipe: 4 servings with 3/2 cups. It means one serving need 3/8 cup. Then the question says "According to the recipe" So I understand it as guidance.

Statement 1: The next time he prepare this dish, Malik will make half as many servings as he did the last time he prepared the dish.
We know nothing about last time. Insufficient

Statement 2: Malik used 6 cups of pasta the last time he prepared this dish.
Here I sued the recipe as the question referred to it, when said 'according the recipe". So here my work.
If 1 serving need 3/8 cup so 6 cups means 16 servings. However, I do not know how many will be served NEXT TIME. Insufficient

Combine 1 & 2
Next time serving = 1/2 Last time = 8
'to make 8 servings, we need 3 cups.

Is that solution above correct, I understood from you explanation to ignore the recipe given in the stem?

Thanks in advance

[[email protected]]

Hi Mo2men,

Yes, your solution is correct.

The recipe "formula" IS relevant (I didn't ignore it), since it links the number of cups of pasta to the number of servings that are made (which is why we can 'connect' Fact 1 and Fact 2). If you recognize how the information connects, then you don't actually have to do any of that math to know that the correct answer is C.

GMAT assassins aren't born, they're made,
Rich