4 times the sum of a number y and 7 is equal to 44. Which equation represents this situation?
GMAT Algebra : (Alg) Questions
4 times the sum of a number \(\mathrm{y}\) and \(\mathrm{7}\) is equal to \(\mathrm{44}\). Which equation represents this situation?
\(\mathrm{4y + 7 = 44}\)
\(\mathrm{4(y + 7) = 44}\)
\(\mathrm{7y + 4 = 44}\)
\(\mathrm{4 + y + 7 = 44}\)
1. TRANSLATE the problem information piece by piece
- Given statement: "4 times the sum of a number y and 7 is equal to 44"
- Let's break this down systematically:
- "a number y" → simply \(\mathrm{y}\)
- "the sum of a number y and 7" → \(\mathrm{y + 7}\)
- "4 times the sum..." → \(\mathrm{4(y + 7)}\)
- "...is equal to 44" → \(\mathrm{= 44}\)
2. INFER why parentheses are crucial
- The phrase "4 times the sum" tells us that 4 multiplies the entire result of adding \(\mathrm{y}\) and 7
- Without parentheses, \(\mathrm{4y + 7}\) would mean "4 times y, then add 7"
- With parentheses, \(\mathrm{4(y + 7)}\) means "first find the sum of \(\mathrm{y}\) and 7, then multiply that whole result by 4"
3. Combine all parts to form the equation
- Putting it all together: \(\mathrm{4(y + 7) = 44}\)
Answer: B. \(\mathrm{4(y + 7) = 44}\)
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skill: Students often translate "4 times the sum of y and 7" as \(\mathrm{4y + 7}\) instead of \(\mathrm{4(y + 7)}\).
They read left to right and translate as they go: "4 times... y" becomes \(\mathrm{4y}\), then "and 7" becomes \(\mathrm{+7}\), giving them \(\mathrm{4y + 7}\). They miss that "4 times" applies to the entire sum, not just to \(\mathrm{y}\).
This leads them to select Choice A (\(\mathrm{4y + 7 = 44}\)).
Second Most Common Error:
Poor TRANSLATE reasoning: Some students get confused about the order of operations and write the numbers in the same sequence they hear them.
They might think "4 times... y and 7" and write \(\mathrm{4 + y + 7}\), completely missing that "times" indicates multiplication and "sum" indicates the \(\mathrm{y}\) and 7 should be added first.
This may lead them to select Choice D (\(\mathrm{4 + y + 7 = 44}\)).
The Bottom Line:
The key challenge is recognizing that "4 times the sum" means the multiplication applies to the entire sum operation, requiring parentheses to group the sum before multiplying.
\(\mathrm{4y + 7 = 44}\)
\(\mathrm{4(y + 7) = 44}\)
\(\mathrm{7y + 4 = 44}\)
\(\mathrm{4 + y + 7 = 44}\)