Esther bought a computer at a price of p dollars, and she paid a sales tax of t percent. If...
GMAT Data Sufficiency : (DS) Questions
Esther bought a computer at a price of \(\mathrm{p}\) dollars, and she paid a sales tax of \(\mathrm{t}\) percent. If Esther had less than \(\mathrm{r}\) dollars left of the $1,000 that she budgeted for the computer, was the price of the computer, excluding the sales tax, greater than $800?
- \(\mathrm{r} = 200\)
- \(\mathrm{t} = 6\)
Understanding the Question
Esther budgeted \(\$1{,}000\) for a computer purchase. She bought a computer at price p dollars plus sales tax of t percent. After the purchase, she had less than r dollars remaining from her budget.
What we need to determine: Is \(\mathrm{p} > \$800\)?
This is a yes/no question. To be sufficient, we need to definitively answer either "Yes, p must be greater than \(\$800\)" or "No, p cannot be greater than \(\$800\)" in all possible scenarios.
Key insight: Since Esther has less than r dollars left from her \(\$1{,}000\) budget, she spent more than \(\$(1{,}000 - \mathrm{r})\) in total. This total spending equals the price p plus the tax, which is \(\mathrm{p} \times (1 + \mathrm{t}/100)\).
Analyzing Statement 1
Statement 1 tells us: \(\mathrm{r} = 200\)
This means Esther has less than \(\$200\) remaining, so she spent more than \(\$800\) total (including tax).
What we still don't know: The tax rate t
Let's test different scenarios to see if we can determine whether \(\mathrm{p} > \$800\):
- Scenario 1: If tax rate = 0%
- Total spent > \(\$800\)
- Since there's no tax, price \(\mathrm{p}\) = total spent > \(\$800\)
- Answer: YES, \(\mathrm{p} > \$800\) - Scenario 2: If tax rate = 25%
- Total spent > \(\$800\)
- With 25% tax, this means \(\mathrm{p} \times 1.25 > \$800\)
- So \(\mathrm{p} > \$640\)
- But this only tells us p is greater than \(\$640\)
- Example: p could be \(\$700\) (which is < \(\$800\)) or \(\$900\) (which is > \(\$800\))
- Answer: Can't determine if \(\mathrm{p} > \$800\)
Since different tax rates lead to different conclusions about whether \(\mathrm{p} > \$800\), Statement 1 alone cannot answer our question.
Statement 1 is NOT sufficient.
This eliminates choices A and D.
Analyzing Statement 2
Now let's forget Statement 1 completely and analyze Statement 2 independently.
Statement 2 tells us: \(\mathrm{t} = 6\)
This means the sales tax rate is 6%.
What we still don't know: The value of r (how much money Esther has left)
Let's test different scenarios:
- Scenario 1: If \(\mathrm{r} = 50\) (she has less than \(\$50\) left)
- She spent more than \(\$950\) total
- With 6% tax: \(\mathrm{p} \times 1.06 > \$950\)
- So \(\mathrm{p} > \$950 \div 1.06 \approx \$896\)
- Since \(\$896 > \$800\), we know \(\mathrm{p} > \$800\)
- Answer: YES, \(\mathrm{p} > \$800\) - Scenario 2: If \(\mathrm{r} = 250\) (she has less than \(\$250\) left)
- She spent more than \(\$750\) total
- With 6% tax: \(\mathrm{p} \times 1.06 > \$750\)
- So \(\mathrm{p} > \$750 \div 1.06 \approx \$708\)
- But knowing \(\mathrm{p} > \$708\) doesn't tell us if \(\mathrm{p} > \$800\)
- Example: p could be \(\$720\) (which is < \(\$800\)) or \(\$850\) (which is > \(\$800\))
- Answer: Can't determine if \(\mathrm{p} > \$800\)
Since different values of r lead to different conclusions about whether \(\mathrm{p} > \$800\), Statement 2 alone cannot answer our question.
Statement 2 is NOT sufficient.
This eliminates choice B.
Combining Both Statements
With both statements together, we know:
- \(\mathrm{r} = 200\) (from Statement 1)
- \(\mathrm{t} = 6\) (from Statement 2)
This means:
- Esther has less than \(\$200\) left
- She spent more than \(\$800\) total
- The total includes 6% tax
So we have: \(\mathrm{p} \times 1.06 > \$800\)
To find the minimum possible price:
- If total spent = exactly \(\$800\), then \(\mathrm{p} = \$800 \div 1.06 \approx \$755\)
- But she spent MORE than \(\$800\), so \(\mathrm{p} > \$755\)
Critical question: Does knowing that \(\mathrm{p} > \$755\) tell us whether \(\mathrm{p} > \$800\)?
Let's check with concrete examples:
- Possible scenario 1: \(\mathrm{p} = \$760\)
- This satisfies \(\mathrm{p} > \$755\) ✓
- Total spent: \(\$760 \times 1.06 = \$805.60\) (which is > \(\$800\)) ✓
- But \(\$760 < \$800\)
- Answer: NO, p is not greater than \(\$800\) - Possible scenario 2: \(\mathrm{p} = \$850\)
- This satisfies \(\mathrm{p} > \$755\) ✓
- Total spent: \(\$850 \times 1.06 = \$901\) (which is > \(\$800\)) ✓
- And \(\$850 > \$800\)
- Answer: YES, p is greater than \(\$800\)
Since we can construct valid scenarios with different answers to our yes/no question, even the combined statements cannot definitively answer whether \(\mathrm{p} > \$800\).
The combined statements are NOT sufficient.
This eliminates choice C.
The Answer: E
Neither statement alone nor both statements together provide enough information to determine whether the pre-tax price exceeded \(\$800\). We can only establish that \(\mathrm{p} > \$755\), but this leaves open the possibility that p could be either below or above \(\$800\).
Answer Choice E: "The statements together are not sufficient."