If-3-5-7-n-terms-5-8-11-10-terms-7-then-the-value-of-n-is- Tinku Tara June 14, 2023 None 0 Comments FacebookTweetPin Question Number 18207 by potata8 last updated on 16/Jul/17 If3+5+7+…+nterms5+8+11+…+10terms=7,thenthevalueofnis Answered by Tinkutara last updated on 17/Jul/17 3+5+7+…+(nterms)=n2[6+(n−1)2]=n2(2n+4)=n(n+2)5+8+11+…+(10terms)=102[10+9×3]=5×37=185∴n(n+2)185=7⇒n2+2n−1295=0n=−2±722=−1±36=35or−37∴n=35. Terms of Service Privacy Policy Contact: info@tinkutara.com FacebookTweetPin Post navigation Previous Previous post: If-the-coefficient-of-the-middle-term-in-the-expansion-of-the-1-x-2n-2-is-p-and-the-coefficients-of-middle-terms-in-the-expansion-of-1-x-2n-1-are-q-and-r-then-Next Next post: In-an-1800-m-race-P-beats-Q-by-50-seconds-In-the-same-race-Q-beats-R-by-40-seconds-If-P-beats-R-by-450-m-by-what-distance-does-P-beat-Q-in-m- Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Save my name, email, and website in this browser for the next time I comment.
![3 + 5 + 7 + ... + (n terms) = (n/2)[6 + (n − 1)2] = (n/2)(2n + 4) = n(n + 2) 5 + 8 + 11 + ... + (10 terms) = ((10)/2)[10 + 9×3] = 5×37 = 185 ∴ ((n(n + 2))/(185)) = 7 ⇒ n^2 + 2n − 1295 = 0 n = ((−2 ± 72)/2) = −1 ± 36 = 35 or −37 ∴ n = 35.](https://www.tinkutara.com/question/Q18218.png)