Which term of the AP : 3, 8, 13, 18, . . . , is 78? – InterviewSolution

InterviewSolution

1.	Which term of the AP : 3, 8, 13, 18, . . . , is 78?
Answer» Here, `a = 3, d = 5 and a_n = 78` We know, `a_n = a+(n-1)d` `=>78 = 3+5(n-1)=>n-1 = 15` `=>n=16` So, `16^(th)` term is the required term.

Discussion

No Comment Found

Related InterviewSolutions

Determine k, so that `K^(2)+4k+8, 2k^(2)+3k+6` and `3k^(2)+4k+4` are three consecutive terms of an AP.
Find the 9th term from the ctowards the first term of the A.P. 5,9,13,....,185
A sum of Rs 700 is to be used to give seven cash prizes to students of a school for their overall academic performance. If each prize is Rs 20 less than its preceding prize, find the value of each of the prizes.
A shop keeper buys a number of books for Rs.80. If he had bought 4 more books for the same amount, each book would have cost his Rs.1 less .How many books did he buy?
The third term and nineth terms of an A.P. are 4 and -8 respectively. Find which term of A.P is equal to 0.
If `a_(n)=3-4n`, then show that `a_(1),a_(2),a_(3), …` form an AP. Also, find `S_(20)`.
The first , second and the last terms of an A.P. are `a ,b , c`respectively. Prove that the sum is `((a+c)(b+c-2a))/(2(b-a))`.
Find the `11^(t h)`from the last term (towards the first term) of the AP : `10 , 7, 4, dot dot dot , 62.`
We know that the sum of the interior angles of a triangle is`180^0`. Show that the sums of the interior angles of polygons with `3,4,5,6`sides form an arithmetic progression. Find the sum of the interior angles ofa 21 sided polygon.
Check whether ` 150` is a term of the AP : 11, 8, 5, 2...