Difficulty: Medium
Correct Answer: 50
Explanation:
Introduction / Context:
This question involves understanding money in rupees and paise and setting up a quadratic equation. Each member contributes an amount that depends on the total number of members, and you are asked to find that number given the total contribution.
Given Data / Assumptions:
• Let the number of members in the club be n.• Each member contributes n rupees and n paise.• Total contribution from all members is Rs 2525.• We use 100 paise = 1 rupee.
Concept / Approach:
If there are n members, and each gives n rupees and n paise, then each member contributes n + n/100 rupees. The total contribution is n times this amount. This leads to a quadratic equation in n, which we solve to find the number of members. We also check that the solution is a positive integer that makes sense in the context of the problem.
Step-by-Step Solution:
Step 1: Let the number of members be n.Step 2: Each member contributes n rupees and n paise.Step 3: Convert n paise to rupees: n paise = n / 100 rupees.Step 4: So contribution per member in rupees = n + n / 100 = (100n + n) / 100 = 101n / 100.Step 5: Total contribution from n members = n * (101n / 100) rupees.Step 6: Given total contribution = Rs 2525, so n * (101n / 100) = 2525.Step 7: Multiply both sides by 100: 101n^2 = 2525 * 100 = 252500.Step 8: Divide both sides by 101: n^2 = 252500 / 101.Step 9: Note that 101 * 2500 = 252500, so n^2 = 2500.Step 10: Therefore, n = square root of 2500 = 50 (reject negative value).
Verification / Alternative check:
If n = 50, then each member contributes 50 rupees and 50 paise. In rupees, that is 50.50 or 50 + 50 / 100. Total contribution = 50 * 50.50 = 50 * 50.5 = 2525, which matches the given total. This confirms that n = 50 is correct.
Why Other Options Are Wrong:
60, 45, 55: Substituting these values into the expression n * (101n / 100) does not yield 2525. The resulting totals differ from the given amount, so these cannot be the correct number of members.
Common Pitfalls:
Some students forget to convert paise into rupees or misinterpret the phrase as n rupees or n paise instead of both. Others may make algebraic mistakes when forming or solving the quadratic equation. Careful unit conversion and stepwise algebra help avoid errors.
Final Answer:
The number of members in the club is 50.
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