True Discount known (8 months) → Banker’s Discount: The true discount on a bill of Rs. 1860 due after 8 months is Rs. 60. Find the banker's discount.
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ARs . 62
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BRs .52
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CRs . 60
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DNone of these
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ERs . 64
Answer
Correct Answer: Rs . 62
Explanation
Introduction / Context:Given True Discount (TD) on a known face value F for a given time, we can back out x = r * t using TD = F * x / (1 + x). With x, we find Banker's Discount via BD = F * x.
Given Data / Assumptions:
- F = Rs. 1860.
- t = 8 months ⇒ t = 8/12 years = 2/3 years.
- TD = Rs. 60; simple interest.
Concept / Approach:Let x = r * t. From TD relation, solve for x and compute BD.
Step-by-Step Solution:TD = F * x / (1 + x) ⇒ 60 = 1860 x / (1 + x).1860 x = 60 + 60 x ⇒ 1800 x = 60 ⇒ x = 1/30.BD = F * x = 1860 * (1/30) = Rs. 62.
Verification / Alternative check:P = F − TD = 1860 − 60 = 1800; also P = F / (1 + x) = 1860 / (1 + 1/30) = 1860 / (31/30) = 1800, consistent.
Why Other Options Are Wrong:Rs. 52 and Rs. 60 do not satisfy BD = F * x with x = 1/30; "None of these" is unnecessary.
Common Pitfalls:Solving for r instead of x = r * t; arithmetic slips when isolating x.
Final Answer:Rs . 62