1c:I[1254,["7330","static/chunks/d3ac728e-78c3d5d7a486ed3a.js","5159","static/chunks/5159-48592f0bf1a47f9d.js","8175","static/chunks/8175-f84d59b9bd013e10.js","8167","static/chunks/8167-b25693a0140130f2.js","664","static/chunks/664-f64584b506570f6e.js","3703","static/chunks/app/practice-question/%5Bslug%5D/page-d1408559b663b83f.js"],"PracticeQuestionCard"] 1b:T4d6,{"@context":"https://schema.org","@type":"QAPage","name":"The sum of 10 terms of the arithmetic series is 390. If the third ter…","url":"https://vidyalelo.com/practice-question/the-sum-of-10-terms-of-the-arithmetic-series-is-390-if-the-third-term-of-the-series-is-19-find-the-first-term-246358","keywords":"practice questions, MCQ, MCQs with answers, objective questions, competitive exam questions, Competitive Exams, Competitive Exams MCQ, Competitive Exams MCQs, Competitive Exams questions, Competitive Exams practice questions, Aptitude, Aptitude MCQ, Aptitude MCQs, Aptitude questions, Aptitude practice questions, Number System","mainEntity":{"@type":"Question","name":"The sum of 10 terms of the arithmetic series is 390. If the third ter…","text":"The sum of 10 terms of the arithmetic series is 390. If the third term of the series is 19. Find the first term?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Option A. 3. Answer & Solution Answer: Option A Solution: & Sum of A .P . = n/2 [ 2a + ( n - 1 )d ] & n^ th term = a + ( n - 1 )d & 3^ rd term = a + ( 3 - 1 )d = 19 & a + 2d = 19\\,......\\, ( i ) & Sum of 10 term = 102 [ 2a + 9d ] = 390 & 2a + 9d = 78\\,......\\, ( ii ) & a + 2d = 19\\,......\\,…"}}}1d:T44e,

Answer & Solution

Answer: Option A

Solution:

$$\eqalign{ & {\text{Sum of A}}{\text{.P}}{\text{.}} = \frac{n}{2}\left[ {2a +