In an ap a 1 an 20 sn 399
WebSum of n terms of AP is given by: S n = n 2 2 a 1 + n-1 d where a 1 = first term, d = common difference. S 24-4 = 24-4 2 2 × 1 + 24-4-1 13 ∵ d = 13, n = 24, a 1 = 1 S 20 = 20 2 2 + 19 × 13 = 2490. a n-4 = a 1 + n-4-1 d a 24-4 = 1 + 24-4-1 13 ∵ d = 13, n = 24, a 1 = 1 a 20 = 248. Therefore, the ordered pair S n-4, a n-4 is equal to (2490 ... WebFeb 22, 2013 · In an A.P. , if a = 1, an= 20 and sn =399, then n is? Share with your friends 1 Follow 0 Jai Prakash, added an answer, on 22/2/13 we know from that formula that, Sn = n/2 (a + an) 399 = n/2 (1 + 20) 399*2 = n (21) n = 798/21 = 38 Therefore n = 38 Was this answer helpful? 3 View Full Answer
In an ap a 1 an 20 sn 399
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WebMar 11, 2024 · answered In an Ap, a=1, an=20, sn=399 then find n Advertisement Answer 3 people found it helpful pragyanrana31 Answer: Sn=n/2 (a+l) . . 399=n/2 (1+20) . . 399*2/21=n . . 19*2=n . . N=38 . . Hope this helps you . . Pls mark Brainliest answer! ️ Find Math textbook solutions? Class 6 Class 5 Class 4 Class 3 Class 2 Class 1 NCERT Class 9 …
WebIn an AP if a = 1, an = 20 and Sn = 399, then n is (A) 19 (B) 21 (C) 38 (D) 42. The sum of first five multiples of 3 is ... Also find S 20. In an AP, if Sn = n (4n + 1), find the AP. 54 EXEMPLAR PROBLEMS. In an AP, if Sn = 3n 2 + 5n and ak = 164, find the value of k. If Sn denotes the sum of first n terms of an AP, prove that. S 12 = 3(S 8 –S 4 ) WebFeb 27, 2012 · In an AP if a=1, an= 20 and sn =399 then n is a) 13 b) 38 c) 21 - Maths - Arithmetic Progressions - 1833845 Meritnation.com Class-10 » Maths Arithmetic …
WebMar 28, 2024 · Objectives: This study aims to investigate the risk factors associated with severity and death from COVID-19 through a systematic review and meta-analysis of the published documents in Iran.Methods: A systematic search was performed based on all articles indexed in Scopus, Embase, Web of Science (WOS), PubMed, and Google Scholar … WebIn an AP if a = 1, a n = 20 and S n = 399, then n is 38. Explanation: ∵ S n = n 2 [ 2 a + ( n - 1) d] 339 = n 2 [ 2 × 1 + ( n - 1) d] 798 = 2 n + n ( n - 1) d ........ (i) And a n = 20 ⇒ a + ( n - 1) d = …
WebAnswer : Let the required numbers in A.P.are (a - d), a and (a + d). Sum of these numbers = (a - d) + a + (a + d) = 3a Product of these numbers = (a - d)× a × (a + d)=a (a 2 - d 2) But given, sum = 24 and product = 440 ∴ 3a = 24 a = 8 and a (a 2 - d 2) = 8 (64 - d 2) = 440 [ a = 8] Or, 64 - d 2 = 55 Or, d 2 = 64 - 55 => d 2 = 9 => d = ± 3
WebOct 25, 2015 · In an AP, if a=1,an=20 and Sn= 399, then n=? Advertisement Expert-Verified Answer 603 people found it helpful Brainly User since , an = a+ (n-1)d 20 = 1 + (n-1)d 19 = … tss holidays 2023WebIn an AP, if a =1, an, = 20 and Sn = 399, then find n. ← Prev Question Next Question → +1 vote . 6.6k views. asked Feb 1, 2024 in Mathematics by Kundan kumar (51.5k points) In an … phividaWebIf an A.P. has a = 1, t n = 20 and s n = 399, then value of n is : A. 20 B. 32 C. 38 D. 40 Answer: Option C Solution (By Examveda Team) S n = 1 2 ( a + l) × n ⇒ 399 = ( 1 + 20) × n 2 ⇒ 399 × 2 = 21 × n ⇒ n = 399 × 2 21 ⇒ n = 19 × 2 ⇒ n = 38 Join The Discussion Related Questions on Progressions How many terms are there in 20, 25, 30 . . . . . . 140? tsshonline.weebly.comWebIn an AP if a = 1, an = 20 and Sn = 399, then n is _____. CBSE English Medium Class 10. Question Papers 939. Textbook Solutions 33590. MCQ Online Mock Tests 12. Important … phiviWeb20.(本小题满分14分)已知等差数列 an 的公差d 0,它的前n项和为Sn,若 ... 8 Sn . y2. 1的左、右两个顶点分别为A、B.曲21.(本小题满分14分)已知椭圆x 4. 2. 线C是以A、B. P在第一象限且在曲线C上,直线AP与椭圆相交于另一点T. (1)求曲线C的方程; ... tss hoodWebSolution: An arithmetic progression (AP) is a sequence where the two consecutive terms have the same common difference. It is obtained by adding the same fixed number to its previous term. The nth term of an AP is. aₙ = a + (n - 1 )d. a = first term. aₙ = nth term. d = common difference. Considering the question, we get the value as, tss hondaWebIn an AP, if a = 1, an = 20 and Sn = 399, then n is equal to (a) 19 (b) 21 (c) 38 (d) 42 Solution: Question 18: The sum of first five multiples of 3 is (a) 45 (b) 55 (c) 65 (d) 75 Solution: (a) The first five multiples of 3 are 3, 6, 9,12 and 15. Here, first term, a = 3, common difference, d = 6-3 = 3 and number of terms, n = 5 tss home page