Data Sufficiency — Salaries and Average (Five Persons) In a group of five employees A, B, C, D, and E, the average salary is ₹ 65,780 (so the total of all five salaries is fixed). What is the exact salary of A? I. The combined salary of B and C equals ₹ 88,545. II. The combined salary of D and E equals ₹ 59,020.

Difficulty: Medium

Correct Answer: Both statements I and II together are sufficient, but neither alone is sufficient.

Explanation:


Introduction / Context:
This is a classic data sufficiency problem on averages and totals. We are not asked to compute a numerical salary for A directly unless forced; instead, we must judge whether the given statements provide enough information to determine A uniquely.


Given Data / Assumptions:

  • Average salary of five people (A, B, C, D, E) is ₹ 65,780.
  • Therefore, total T = 5 * 65,780.
  • Statement I: (B + C) = ₹ 88,545.
  • Statement II: (D + E) = ₹ 59,020.


Concept / Approach:
Averages convert to totals via T = average * count. If we know T and the sum of everyone except A, then A = T - (sum of others). We check whether each statement isolates (B + C + D + E).


Step-by-Step Solution:

1) Compute total: T = 5 * 65,780 = 328,900.2) From I alone, we only know (B + C); (D + E) remains unknown ⇒ cannot get (B + C + D + E).3) From II alone, we only know (D + E); (B + C) remains unknown ⇒ cannot get (B + C + D + E).4) Using I and II together: (B + C + D + E) = 88,545 + 59,020 = 147,565.5) Then A = T - (B + C + D + E) = 328,900 - 147,565 = 181,335 (unique).


Verification / Alternative check:
Once both partial sums are known, A is uniquely determined by subtraction from T. No other values can change A without changing I or II, so the solution is unique.


Why Other Options Are Wrong:

  • Statement I alone sufficient: Wrong — lacks (D + E).
  • Statement II alone sufficient: Wrong — lacks (B + C).
  • Either one alone sufficient: Wrong — each alone is missing two salaries.
  • Even both not sufficient: Wrong — together they fully determine A.


Common Pitfalls:
Confusing “average” with individual values; forgetting to multiply average by count; assuming extra information not given about individuals; or trying to compute everyone’s salary instead of only establishing sufficiency for A’s salary.


Final Answer:
Both statements together are sufficient; neither alone is sufficient.

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