A bakery owner made a profit of $139 on custom cakes after deducting a fixed overhead cost of $29 and...
GMAT Algebra : (Alg) Questions
A bakery owner made a profit of \(\$139\) on custom cakes after deducting a fixed overhead cost of \(\$29\) and selling \(\mathrm{p}\) cakes at \(\$12\) each. Which of the following equations represents this situation?
\(12\mathrm{p} - 29 = 139\)
\(29\mathrm{p} - 12 = 139\)
\(12\mathrm{p} + 29 = 139\)
\(29\mathrm{p} + 12 = 139\)
1. TRANSLATE the problem information
- Given information:
- Profit made: $139
- Fixed overhead cost: $29 (this gets deducted)
- Revenue: \(\mathrm{p}\) cakes sold at $12 each = \(\mathrm{12p}\) dollars
2. INFER the relationship between profit, revenue, and costs
- The key insight: \(\mathrm{Profit = Revenue - Costs}\)
- Revenue comes from selling cakes: \(\mathrm{12p}\)
- The overhead cost of $29 is subtracted from revenue
- So: \(\mathrm{Profit = 12p - 29}\)
3. Set up the equation
- We know the profit is $139
- Therefore: \(\mathrm{12p - 29 = 139}\)
Answer: A
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skill: Students misinterpret "after deducting a fixed overhead cost" and think this means the cost gets added to the profit rather than subtracted from the revenue.
Their reasoning: "The profit is $139 and there's also a $29 cost, so the total is \(\mathrm{12p = 139 + 29}\)."
This may lead them to select Choice C (\(\mathrm{12p + 29 = 139}\)).
Second Most Common Error:
Poor TRANSLATE reasoning: Students mix up which numbers represent the price per cake versus the overhead cost, thinking the $29 is the price per cake and $12 is the overhead.
This confusion about which number goes where leads them to set up equations like \(\mathrm{29p - 12 = 139}\).
This may lead them to select Choice B (\(\mathrm{29p - 12 = 139}\)) or Choice D (\(\mathrm{29p + 12 = 139}\)).
The Bottom Line:
This problem tests whether students can correctly translate a business scenario into algebra while keeping track of what each number represents and understanding that profit means "what's left after subtracting costs."
\(12\mathrm{p} - 29 = 139\)
\(29\mathrm{p} - 12 = 139\)
\(12\mathrm{p} + 29 = 139\)
\(29\mathrm{p} + 12 = 139\)