Sachin invested some amount in a National Saving Certificate Scheme. In the first year he invested ₹ 5,000, in the second year ₹ 7,000, in the third year ₹ 9,000 and so on. Find the total amount that he invested in 12 years.

Q.3 (B)(ii) Sachin invested some amount in a National Saving Certificate Scheme. In the first year he invested ₹ 5,000, in the second year ₹ 7,000, in the third year ₹ 9,000 and so on. Find the total amount that he invested in 12 years.

Doubtly Asked 25 Oct 2026 ssc 10th Save WhatsApp Report

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Answer: ₹ 1,92,000

The yearly investments 5000, 7000, 9000, … form an A.P. with \(a = 5000\), \(d = 2000\), \(n = 12\).

\(S_n = \dfrac{n}{2}[2a + (n - 1)d]\)

\(S_{12} = \dfrac{12}{2}[2(5000) + (12 - 1)(2000)] = 6[10{,}000 + 22{,}000]\)

\(S_{12} = 6 \times 32{,}000 = \) ₹ 1,92,000.

Doubtly AI · 25 Oct 2026 AI-verified · Oct 2026 Report

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Sachin invested some amount in a National Saving Certificate Scheme. In the first year he invested ₹ 5,000, in the second year ₹ 7,000, in the third year ₹ 9,000 and so on. Find the total amount that he invested in 12 years.

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