e-GMAT Logo
NEUR
N

The 50 participants of a management training seminar ate dinner at a certain restaurant. They had 3 choices for their...

GMAT Data Sufficiency : (DS) Questions

Source: Mock
Data Sufficiency
DS - Money
HARD
...
...
Notes
Post a Query

The \(50\) participants of a management training seminar ate dinner at a certain restaurant. They had \(3\) choices for their meal: vegetarian lasagna for \(\$12\), blackened catfish for \(\$15\), or stuffed pork chops for \(\$18\). Each participant ordered exactly \(1\) meal and the total cost of the meals ordered by the participants was \(\$810\). How many participants of the management training seminar ordered blackened catfish?

  1. Six more people ordered catfish than lasagna.
  2. Twice as many pork chop meals were ordered as catfish meals.
A
Statement (1) ALONE is sufficient but statement (2) ALONE is not sufficient.
B
Statement (2) ALONE is sufficient but statement (1) ALONE is not sufficient.
C
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D
EACH statement ALONE is sufficient.
E
Statements (1) and (2) TOGETHER are not sufficient.
Solution

Understanding the Question

We need to find the exact number of participants who ordered blackened catfish.

Given Information

  • Total participants: 50
  • Three meal choices with fixed prices:
    • Vegetarian lasagna: $12
    • Blackened catfish: $15
    • Stuffed pork chops: $18
  • Each participant ordered exactly 1 meal
  • Total cost of all meals: $810

What We Need to Determine

To answer "How many participants ordered blackened catfish?", we need a unique value for the number of catfish orders.

Let's define:

  • \(\mathrm{L} = \mathrm{number\ who\ ordered\ lasagna}\)
  • \(\mathrm{C} = \mathrm{number\ who\ ordered\ catfish}\)
  • \(\mathrm{P} = \mathrm{number\ who\ ordered\ pork\ chops}\)

From our given information:

  • \(\mathrm{L + C + P = 50}\) (total participants)
  • \(\mathrm{12L + 15C + 18P = 810}\) (total cost)

Key Insight

With 2 equations and 3 unknowns, we need one more independent constraint to find a unique value for C. Think of it this way: we know the total headcount and total bill, but there are multiple ways to distribute 50 people among three meals to reach $810.

Analyzing Statement 1

Statement 1: Six more people ordered catfish than lasagna.

What Statement 1 Tells Us

This gives us the relationship: \(\mathrm{C = L + 6}\)

Now we have a third equation! This creates a system of 3 equations with 3 unknowns, which typically has a unique solution.

Solving the System

From \(\mathrm{C = L + 6}\), we get \(\mathrm{L = C - 6}\)

Substituting into our participant equation:

  • \(\mathrm{(C - 6) + C + P = 50}\)
  • \(\mathrm{2C + P = 56}\)
  • \(\mathrm{P = 56 - 2C}\)

Now substituting both expressions into the cost equation:

  • \(\mathrm{12(C - 6) + 15C + 18(56 - 2C) = 810}\)
  • \(\mathrm{12C - 72 + 15C + 1008 - 36C = 810}\)
  • \(\mathrm{-9C + 936 = 810}\)
  • \(\mathrm{-9C = -126}\)
  • \(\mathrm{C = 14}\)

Verification

Let's verify our answer:

  • \(\mathrm{C = 14}\) (catfish orders)
  • \(\mathrm{L = 14 - 6 = 8}\) (lasagna orders)
  • \(\mathrm{P = 56 - 2(14) = 28}\) (pork chop orders)

Check: \(\mathrm{8 + 14 + 28 = 50}\)
Cost: \(\mathrm{12(8) + 15(14) + 18(28) = 96 + 210 + 504 = 810}\)

Conclusion

Statement 1 provides enough information to determine that exactly 14 participants ordered catfish.

[STOP - Statement 1 is Sufficient!]

This eliminates choices B, C, and E.

Analyzing Statement 2

Important: We now forget Statement 1 completely and analyze Statement 2 independently.

Statement 2: Twice as many pork chop meals were ordered as catfish meals.

What Statement 2 Provides

This gives us: \(\mathrm{P = 2C}\)

Again, we have a third equation, creating a solvable system.

Solving the System

From \(\mathrm{P = 2C}\) and our participant equation:

  • \(\mathrm{L + C + 2C = 50}\)
  • \(\mathrm{L + 3C = 50}\)
  • \(\mathrm{L = 50 - 3C}\)

Substituting into the cost equation:

  • \(\mathrm{12(50 - 3C) + 15C + 18(2C) = 810}\)
  • \(\mathrm{600 - 36C + 15C + 36C = 810}\)
  • \(\mathrm{600 + 15C = 810}\)
  • \(\mathrm{15C = 210}\)
  • \(\mathrm{C = 14}\)

Verification

Let's verify this solution:

  • \(\mathrm{C = 14}\) (catfish orders)
  • \(\mathrm{P = 2(14) = 28}\) (pork chop orders)
  • \(\mathrm{L = 50 - 3(14) = 8}\) (lasagna orders)

Check: \(\mathrm{8 + 14 + 28 = 50}\)
Cost: \(\mathrm{12(8) + 15(14) + 18(28) = 96 + 210 + 504 = 810}\)

Conclusion

Statement 2 also provides enough information to determine that exactly 14 participants ordered catfish.

[STOP - Statement 2 is Sufficient!]

The Answer: D

Both statements independently provide enough information to determine that 14 participants ordered blackened catfish.

Answer Choice D: "Each statement alone is sufficient."

Answer Choices Explained
A
Statement (1) ALONE is sufficient but statement (2) ALONE is not sufficient.
B
Statement (2) ALONE is sufficient but statement (1) ALONE is not sufficient.
C
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D
EACH statement ALONE is sufficient.
E
Statements (1) and (2) TOGETHER are not sufficient.
Rate this Solution
Tell us what you think about this solution
...
...
Forum Discussions
Start a new discussion
Post
Load More
Similar Questions
Finding similar questions...
Previous Attempts
Loading attempts...
Similar Questions
Finding similar questions...
Parallel Question Generator
Create AI-generated questions with similar patterns to master this question type.