Question

sachin invested in a national saving certificate scheme. in the first year be invested ₹500. in the second year ₹700, in the third year ₹900 and so on find the total amount that he invested in 12 years​

Answer 1

$\huge \bf \underline \red{→ solution}$

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→ Amount invested by Sachin in each year are as follows:

: 5000, 7000, 9000,

『 → above sequence is an A.P』

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∴ a = 5000,

d = 7000 – 5000 = 2000,

n = 12 ii. Sn = n/2 [ 2a + (n - 1)d ]

∴ S12 = 12/2 [2(5000) + (12-1) 2000] = 6(10000 + 11 x 2000) = 6( 10000 + 22000) = 6(32000)

∴ s12 = 192000

{∴ → The total amount invested by Sachin in 12 years is Rs. 1,92,000.

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