In a set of four consecutive odd integers, where the integers are ordered from least to greatest, the first integer...
GMAT Algebra : (Alg) Questions
In a set of four consecutive odd integers, where the integers are ordered from least to greatest, the first integer is represented by \(\mathrm{x}\). The product of \(\mathrm{12}\) and the fourth odd integer is at most \(\mathrm{26}\) less than the sum of the first and third odd integers. Which inequality represents this situation?
1. TRANSLATE the problem information
- Given information:
- Four consecutive odd integers ordered from least to greatest
- First integer is represented by x
- Product of 12 and the fourth odd integer ≤ 26 less than sum of first and third integers
2. INFER the pattern for consecutive odd integers
- Since we're dealing with consecutive odd integers, each integer is 2 more than the previous one
- This gives us: \(\mathrm{x, x+2, x+4, x+6}\)
3. TRANSLATE each part of the condition
- "Product of 12 and the fourth odd integer" = \(\mathrm{12(x + 6)}\)
- "Sum of the first and third odd integers" = \(\mathrm{x + (x + 4)}\)
- "26 less than" this sum = \(\mathrm{x + (x + 4) - 26}\)
- "at most" means we use ≤
4. TRANSLATE the complete inequality
- The product is at most 26 less than the sum:
\(\mathrm{12(x + 6) \leq x + (x + 4) - 26}\)
Answer: A
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skills: Students misinterpret "at most 26 less than" and flip the inequality direction or rearrange the expression incorrectly.
Instead of recognizing that "\(\mathrm{Product \leq Sum - 26}\)," they might think "\(\mathrm{Product \geq 26 - Sum}\)" and rearrange terms. This leads to setting up the inequality as \(\mathrm{12(x + 6) \geq 26 - (x + (x + 4))}\).
This may lead them to select Choice B (\(\mathrm{12(x + 6) \geq 26 - (x + (x + 4))}\))
Second Most Common Error:
Missing conceptual knowledge: Students forget that consecutive odd integers differ by 2, not 1.
They might think the integers are \(\mathrm{x, x+1, x+2, x+3}\), but then realize these aren't all odd and get confused about the correct pattern. This confusion can cause them to abandon systematic solution and start guessing.
The Bottom Line:
This problem requires careful translation of complex language involving inequalities and a solid understanding of integer sequences. Students must parse multiple layers of mathematical language while keeping track of which integer is which.