Connor has c dollars and Maria has m dollars. Connor has 4 times as many dollars as Maria, and together...
GMAT Algebra : (Alg) Questions
Connor has \(\mathrm{c}\) dollars and Maria has \(\mathrm{m}\) dollars. Connor has 4 times as many dollars as Maria, and together they have a total of \(\$25.00\). Which system of equations represents this situation?
\(\mathrm{c = 4m}\)
\(\mathrm{c + m = 25}\)
\(\mathrm{m = 4c}\)
\(\mathrm{c + m = 25}\)
\(\mathrm{c = 25m}\)
\(\mathrm{c + m = 4}\)
\(\mathrm{m = 25c}\)
\(\mathrm{c + m = 4}\)
1. TRANSLATE the problem information
- Given information:
- Connor has c dollars, Maria has m dollars
- "Connor has 4 times as many dollars as Maria"
- "together they have a total of $25.00"
2. TRANSLATE each relationship into an equation
- "Connor has 4 times as many dollars as Maria":
This means Connor's amount = 4 × Maria's amount
So: \(\mathrm{c = 4m}\)
- "together they have a total of $25.00":
This means Connor's amount + Maria's amount = 25
So: \(\mathrm{c + m = 25}\)
3. INFER that we need both equations together
- Since both conditions must be true at the same time, we need a system of equations:
\(\mathrm{c = 4m}\)
\(\mathrm{c + m = 25}\)
4. Match with answer choices
Looking at the options, Choice A gives us exactly \(\mathrm{c = 4m}\) and \(\mathrm{c + m = 25}\).
Answer: A
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skill: Students misinterpret "Connor has 4 times as many dollars as Maria" and write \(\mathrm{m = 4c}\) instead of \(\mathrm{c = 4m}\).
The phrase "Connor has 4 times as many" means Connor's amount equals 4 times Maria's amount, but students sometimes think it means Maria has 4 times Connor's amount. They get the relationship backwards.
This may lead them to select Choice B (\(\mathrm{m = 4c}\), \(\mathrm{c + m = 25}\)).
Second Most Common Error:
Poor TRANSLATE reasoning: Students mix up which numbers go where, potentially writing equations like \(\mathrm{c = 25m}\) or interpreting the total as $4 instead of $25.
This confusion about which numbers represent the multiplier versus the total can cause them to get stuck and guess, or select Choice C or Choice D.
The Bottom Line:
The key challenge is carefully translating "X has [number] times as many as Y" into the correct equation \(\mathrm{X = [number] \times Y}\), not the reverse. Students must slow down and think about which variable should equal the multiple of the other.
\(\mathrm{c = 4m}\)
\(\mathrm{c + m = 25}\)
\(\mathrm{m = 4c}\)
\(\mathrm{c + m = 25}\)
\(\mathrm{c = 25m}\)
\(\mathrm{c + m = 4}\)
\(\mathrm{m = 25c}\)
\(\mathrm{c + m = 4}\)