Question

12, 14, 16, 18, 20, ......... या अंकगणिती श्रेढीच्या पहिल्या 100 पदांची बेरीज करा.

कृती: येथे, a = 12, d = `square` n = 100, S₁₀₀ = ?

S_n = `"n"/2[square + ("n" - 1)"d"]`

S₁₀₀ = `square/2`[24 + (100 – 1)d]

= 50 (24 + `square`)

= `square`

= `square`

Answer 1

येथे, a = 12, d = 14 - 12 = 2, n = 100, S₁₀₀ = ?

S_n = `"n"/2[underline(2"a") + ("n" - 1)"d"]`

∴ S₁₀₀ = `underline(100)/2`[24 + (100 – 1)d] 

= 50 [24 + 99(2)]

= 50 (24 + 198)

= 50(222)

= 11100