Difficulty: Medium
Correct Answer: Rs. 340
Explanation:
Introduction / Context:
This problem involves arithmetic progression and distribution of money. The father distributes Rs. 2000 among five children, with each child getting a fixed amount more than the younger one. The question tests your understanding of arithmetic sequences and how to sum them to match a total amount.
Given Data / Assumptions:
- Total money to be distributed = Rs. 2000.
- There are five children, ordered by age: youngest, then four older children.
- Each child gets Rs. 30 more than the immediately younger child.
- We need the share of the youngest child.
Concept / Approach:
The distribution forms an arithmetic progression (A.P.) of 5 terms with common difference d = Rs. 30. Let the youngest child's share be x. Then the shares will be x, x + 30, x + 60, x + 90, x + 120. The sum of these five amounts must equal Rs. 2000. We set up that equation and solve for x.
Step-by-Step Solution:
Step 1: Let the youngest child's share be x rupees.Step 2: Then 2nd child gets x + 30, 3rd child x + 60, 4th child x + 90, and the eldest x + 120.Step 3: Total sum of all 5 shares: x + (x + 30) + (x + 60) + (x + 90) + (x + 120).Step 4: Combine like terms: 5x + (30 + 60 + 90 + 120) = 5x + 300.Step 5: Given that this total is Rs. 2000, write the equation: 5x + 300 = 2000.Step 6: Subtract 300 from both sides: 5x = 1700.Step 7: Solve for x: x = 1700 / 5 = 340.
Verification / Alternative check:
Check by listing the actual amounts: youngest = 340, then 370, 400, 430, 460. Sum = 340 + 370 + 400 + 430 + 460. First add 340 + 460 = 800, 370 + 430 = 800, plus 400 gives 800 + 800 + 400 = 2000. The distribution matches the total Rs. 2000, confirming the calculation.
Why Other Options Are Wrong:
Values like Rs. 175, Rs. 260, Rs. 290 or Rs. 325 would not produce a total of Rs. 2000 when you form a 5-term A.P. with common difference Rs. 30. They typically come from arithmetic mistakes, such as mis-summing the common difference or incorrectly dividing the remaining amount by 5.
Common Pitfalls:
Some students forget that there are five children and mis-apply the difference only four times. Others subtract 30 repeatedly from 2000 instead of setting up a proper A.P. sum. Writing the full list of terms and using basic algebra to sum them is the safest and clearest method.
Final Answer:
The youngest child's share is Rs. 340.
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