At a particular track meet, the ratio of coaches to athletes is 1:26. If there are x coaches at the...
GMAT Problem-Solving and Data Analysis : (PS_DA) Questions
At a particular track meet, the ratio of coaches to athletes is \(1:26\). If there are \(\mathrm{x}\) coaches at the track meet, which of the following expressions represents the number of athletes at the track meet?
\(\frac{\mathrm{x}}{26}\)
\(26\mathrm{x}\)
\(\mathrm{x} + 26\)
\(\frac{26}{\mathrm{x}}\)
1. TRANSLATE the problem information
- Given information:
- Ratio of coaches to athletes is \(\mathrm{1:26}\)
- There are x coaches at the track meet
- Need to find: expression for number of athletes
- What this tells us: For every 1 coach, there are 26 athletes
2. INFER the approach
- Key insight: Ratios must stay constant - if one part changes, the other must change proportionally
- Strategy: Use the scaling property of ratios
3. INFER the scaling relationship
- Original ratio: \(\mathrm{1\ coach : 26\ athletes}\)
- Current situation: \(\mathrm{x\ coaches : ?\ athletes}\)
- Since coaches increased from 1 to x (multiplied by x), athletes must increase from 26 to \(\mathrm{26×x}\) to maintain the same ratio
4. Apply the scaling
- Number of athletes = \(\mathrm{26 × x = 26x}\)
Answer: B (\(\mathrm{26x}\))
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skill: Students misinterpret ratios as addition relationships rather than multiplication relationships.
They think: "If the ratio is 1 to 26, and there are x coaches, then there are x plus 26 more athletes." This fundamental misunderstanding of what ratios represent leads them to select Choice C (\(\mathrm{x + 26}\)).
Second Most Common Error:
Poor TRANSLATE reasoning: Students correctly identify it's a ratio problem but get confused about which direction the ratio goes.
They think: "If coaches to athletes is \(\mathrm{1:26}\), then maybe athletes to coaches would be \(\mathrm{x:26}\), so athletes = \(\mathrm{x/26}\)." This backward thinking about the ratio relationship may lead them to select Choice A (\(\mathrm{x/26}\)).
The Bottom Line:
Ratio problems require understanding that ratios represent multiplicative relationships, not additive ones, and that scaling one part of a ratio requires scaling the other part by the same factor.
\(\frac{\mathrm{x}}{26}\)
\(26\mathrm{x}\)
\(\mathrm{x} + 26\)
\(\frac{26}{\mathrm{x}}\)