There are 250 trees in a park. Of these trees, 6% are birch trees. How many birch trees are in...
GMAT Problem-Solving and Data Analysis : (PS_DA) Questions
There are 250 trees in a park. Of these trees, \(6\%\) are birch trees. How many birch trees are in the park?
1. TRANSLATE the problem information
- Given information:
- Total trees in park: 250
- Percentage that are birch trees: 6%
- Need to find: The actual number of birch trees
2. TRANSLATE the percentage into mathematical form
- "6% of 250 trees" means we multiply 250 by 6%
- Convert the percentage: \(\mathrm{6\% = \frac{6}{100} = 0.06}\)
- Set up calculation: \(\mathrm{250 \times 0.06}\)
3. SIMPLIFY the multiplication
- \(\mathrm{250 \times 0.06 = 15}\)
- Therefore, there are 15 birch trees in the park
Answer: B. 15
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE reasoning: Students see "6%" and think the answer is simply 6, not understanding that percentages represent parts of the whole quantity.
They read "6% are birch trees" and select Choice A (6) because they focus on the number in the percentage rather than calculating what 6% of 250 actually equals.
Second Most Common Error:
Poor TRANSLATE execution: Students misread or miscalculate the percentage, perhaps confusing 6% with a larger percentage like 30%.
If they accidentally calculate 30% of 250 (perhaps misreading 6% as 60% and then thinking 60% ≈ 30%), they get \(\mathrm{250 \times 0.30 = 75}\), leading them to select Choice C (75).
The Bottom Line:
This problem requires students to understand that finding a percentage of a quantity means multiplying the total by the percentage expressed as a decimal or fraction - not just identifying the percentage number itself.