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प्रश्न
An article can be bought by paying Rs. 28,000 at once or by making 12 monthly installments. If the first installment paid is Rs. 3,000 and every other installment is Rs. 100 less than the previous one, find:
- amount of installments paid in the 9th month.
- total amount paid in the installment scheme.
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उत्तर
Number of installments = n = 12
First installment = a = Rs. 3000
Depreciation in installment = d = –100
i Amount of installment paid in the 9th month
= t9
= a + 8d
= 3000 + 8 × (–100)
= 3000 – 800
= Rs. 2200
ii. Total amount paid in the installment scheme
= S12
= `12/2 [2 xx 3000 + 11 xx (-100)]`
= 6[6000 – 1100]
= 6 × 4900
= Rs. 29,400
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