Both restaurants in downtown Rosemond—Sam's Diner and the Main Street Café—offer a lunch special consisting of a sandwich, a dessert,...
GMAT Data Sufficiency : (DS) Questions
Both restaurants in downtown Rosemond—Sam's Diner and the Main Street Café—offer a lunch special consisting of a sandwich, a dessert, and a drink for a set price. Which restaurant offers customers more choices for the lunch special?
- The Main Street Café offers twice as many sandwich choices as Sam's Diner.
- Sam's Diner has 2 more drink choices and 2 more dessert choices than the Main Street Café.
Understanding the Question
Two restaurants in downtown Rosemond offer lunch specials with three components: sandwich, dessert, and drink. We need to determine: Which restaurant offers customers more choices for the lunch special?
Here's the key insight: The total number of different lunch specials equals the product of all component choices. If a restaurant has S sandwich options, D dessert options, and R drink options, then:
- Total lunch special combinations = \(\mathrm{S} \times \mathrm{D} \times \mathrm{R}\)
To answer the question, we need to compare these products for both restaurants. "Sufficient" means we can definitively say which restaurant's product is larger.
Analyzing Statement 1
Statement 1 tells us: The Main Street Café offers twice as many sandwich choices as Sam's Diner.
This gives us one relationship, but we know nothing about the dessert and drink choices at each restaurant. Let's test some scenarios:
Scenario 1: What if both restaurants have equal dessert and drink choices?
- Sam's: 5 sandwiches, 3 desserts, 4 drinks → Total = \(5 \times 3 \times 4 = 60\) choices
- Main Street: 10 sandwiches, 3 desserts, 4 drinks → Total = \(10 \times 3 \times 4 = 120\) choices
- Result: Main Street offers more choices
Scenario 2: What if Sam's has many more desserts and drinks?
- Sam's: 5 sandwiches, 10 desserts, 10 drinks → Total = \(5 \times 10 \times 10 = 500\) choices
- Main Street: 10 sandwiches, 2 desserts, 2 drinks → Total = \(10 \times 2 \times 2 = 40\) choices
- Result: Sam's offers more choices
Since different scenarios lead to different winners, Statement 1 is NOT sufficient.
[STOP - Not Sufficient!] This eliminates choices A and D.
Analyzing Statement 2
Now let's analyze Statement 2 independently (forgetting Statement 1 completely).
Statement 2 tells us: Sam's Diner has 2 more drink choices and 2 more dessert choices than the Main Street Café.
This gives us relationships for desserts and drinks, but tells us nothing about sandwich choices. Let's explore:
Scenario 1: What if both restaurants have equal sandwich choices?
- Main Street: 5 sandwiches, 3 desserts, 4 drinks → Total = \(5 \times 3 \times 4 = 60\) choices
- Sam's: 5 sandwiches, 5 desserts, 6 drinks → Total = \(5 \times 5 \times 6 = 150\) choices
- Result: Sam's offers more choices
Scenario 2: What if Main Street has many more sandwiches?
- Main Street: 20 sandwiches, 3 desserts, 4 drinks → Total = \(20 \times 3 \times 4 = 240\) choices
- Sam's: 2 sandwiches, 5 desserts, 6 drinks → Total = \(2 \times 5 \times 6 = 60\) choices
- Result: Main Street offers more choices
Again, different scenarios produce different winners, so Statement 2 is NOT sufficient.
[STOP - Not Sufficient!] This eliminates choice B.
Combining Statements
Now we use both pieces of information together:
- Main Street has twice as many sandwich choices as Sam's (Statement 1)
- Sam's has 2 more dessert choices and 2 more drink choices than Main Street (Statement 2)
We have competing advantages: Main Street has a multiplicative advantage in one category (\(2 \times\) sandwiches), while Sam's has additive advantages in two categories (+2 desserts, +2 drinks).
The critical question: Does doubling one factor beat adding to two factors? This depends entirely on the base numbers!
Testing with small base numbers:
- Main Street: 2 sandwiches, 1 dessert, 1 drink → Total = \(2 \times 1 \times 1 = 2\) choices
- Sam's: 1 sandwich, 3 desserts, 3 drinks → Total = \(1 \times 3 \times 3 = 9\) choices
- Result: Sam's wins by a large margin (9 vs 2)
Testing with larger base numbers:
- Main Street: 20 sandwiches, 10 desserts, 10 drinks → Total = \(20 \times 10 \times 10 = 2,000\) choices
- Sam's: 10 sandwiches, 12 desserts, 12 drinks → Total = \(10 \times 12 \times 12 = 1,440\) choices
- Result: Main Street wins (2,000 vs 1,440)
Why does this happen? When base numbers are small, adding 2 creates large relative increases (\(1 \rightarrow 3\) is a \(3 \times\) multiplier). When base numbers are large, adding 2 creates small relative increases (\(10 \rightarrow 12\) is only a \(1.2 \times\) multiplier).
Since we can find valid scenarios where either restaurant offers more choices, even with both statements combined, we still cannot definitively answer the question.
[STOP - Not Sufficient!] The statements together are NOT sufficient.
The Answer: E
Even with both statements together, we cannot determine which restaurant offers more lunch special choices because the outcome depends on the actual numbers involved. The multiplicative advantage (\(2 \times\) sandwiches) versus the additive advantages (+2 desserts, +2 drinks) produce different winners depending on the base values.
Answer Choice E: The statements together are not sufficient.