" Q2.In an A.P,if "a=1,a_(n)=20" and "s_(n)=399," then "n" is "

In an AP, if a = 1 , a_(n)= 20 and S_(n) = 399 , then n is equal to

In an AP, if a = 1 , a_(n)= 20 and S_(n) = 399 , then n is equal to

In an A.P. if a=2, t_(n)=34 ,S_(n) =90 , then n=

In an A.P. if a=2, t_(n)=34 ,S_(n) =90 , then n=

In an A.P., if a = 8,a_(4), = 17, S_(n) = 148 then value of n is.

In an A.P., if S_(n) = n(4n + 1), then the value of S_(20) is

In an A.P: given a = 8 , a_(n)= 62, S_(n) = 210 ,find n and d .

The sum of an A.P. is 1 and the nth term is 20. If S_(n)=399 , then n=…..

Choose the correct alternative answer: The first term of an A.P. is 1 and nth term is 20 . If S_n=399 , then n=?

In an A.P: given a_(n) = 4 , d = 2 , S_(n) = -14 , find n and a .