In an A.P., `1^(st)` terms is 1 and the last term is 20. The sum of all terms is 399 then n = …………. A)42 B)38 C)21 D)19

In an A.P, 1st term is 1 and the last term is 20 .The sum of all terms is 399 , then n=…. a) 42 b) 38 c) 21 d) 19

In an A.P. I term is 0 and the last term is 40 . Then sum of all terms is =………. when n=20 .

In an A.P. 19th term is 52 and 38th term is 128. Find the sum of first 56 terms.

In an A.P. 19th term is 52 and 38th term is 128 . Find the sum of first 56 terms.

In an A.P. 19^(th) term is 52 and 38^(th) term is 128, Find sum of first 56 terms.

For an A.P., the first term is 5 and the last is 30. The sum of all the terms is 420. What is the value of n ?

An A.P. has 21 terms. If its 11^(th) term is 25, sum of all the term is :

In an A.P. first two terms are -3,4 then 21^(st) term is………

In an A.P., first term is -5 and last term is 45. If sum of all the numbers in the A.P. is 120, then how many terms are there? What is the common difference.