Banker’s Discount (BD) and Banker’s Gain (BG) on a certain bill are ₹196 and ₹28, respectively. Using standard BD–TD–BG relations for simple interest bills, determine the face value (amount due at maturity) of the bill.

Difficulty: Medium

Correct Answer: ₹ 1176

Explanation:


Introduction / Context:
This question uses the classic relationships among Banker’s Discount (BD), True Discount (TD), Banker’s Gain (BG), and the face value F of a bill under simple interest conventions. We will extract TD and then back-compute F.



Given Data / Assumptions:

  • BD = ₹196.
  • BG = ₹28.
  • All discounts follow simple interest bill-discounting definitions.


Concept / Approach:
Key identities (with x = r * t): BD = F * x, TD = F * x / (1 + x), BG = BD − TD. Also BD/TD = 1 + x and BG = x * TD. If BD and BG are known, TD = BD − BG immediately. Then 1 + x = BD/TD ⇒ x obtained; next F = BD / x.



Step-by-Step Solution:

TD = BD − BG = 196 − 28 = ₹168.BD/TD = 196/168 = 7/6 ⇒ 1 + x = 7/6 ⇒ x = 1/6.BD = F * x ⇒ 196 = F * (1/6) ⇒ F = 196 * 6 = ₹1176.


Verification / Alternative check:
Compute TD from F and x: TD = F*x/(1+x) = 1176*(1/6)/(7/6) = 1176*(1/7) = ₹168; BG = 196 − 168 = ₹28, consistent.



Why Other Options Are Wrong:
₹1200, ₹1376, and ₹1400 do not satisfy BD/TD = 7/6 while keeping BD = ₹196.



Common Pitfalls:
Confusing BD with TD or forgetting that BG = BD − TD; mixing rate and time unnecessarily when x can be inferred from BD/TD.



Final Answer:
₹ 1176

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