A man borrows Rs 8000 and agrees to repay with a total interest of Rs 1360 in 12 monthly instalments. Each instalment being less than the preceding one by Rs 40. Find the amount of the first and last instalment.

A man borrows ₹ 8000 and agrees to repay with a total interest of ₹ 1360 in 12 monthly instalments. Each instalment being less than the preceding one by ₹ 40. Find the amount of the first and last instalment.

Doubtly Asked 24 Oct 2026 Save WhatsApp Report

1 answer

Answer: First instalment ₹ 1000, last instalment ₹ 560

Total to repay \(= 8000 + 1360 = 9360\). Instalments form an A.P. with \(d = -40\), \(n = 12\).

\[S_{12} = \frac{12}{2}[2a + 11(-40)] = 9360\]\[6(2a - 440) = 9360\]\[2a - 440 = 1560,\ a = 1000\]\[t_{12} = 1000 + 11(-40) = 560\]

Doubtly AI · 24 Oct 2026 AI-verified · Oct 2026 Report

Was this answer helpful?

A man borrows Rs 8000 and agrees to repay with a total interest of Rs 1360 in 12 monthly instalments. Each instalment being less than the preceding one by Rs 40. Find the amount of the first and last instalment.

1 answer

Your answer