[" 20.Find an A.P.whose fourth term is 9and the sum of its sixth term and "],[" thirteenth term is 40."]

Find an A.P.whose fourth term is 9 and the sum of its sixth term and thirteenth term is 40.

Find an A.P. whose fourth term is 9 and the sum of its sixth term and thirteenth term is 40.

Find an AP whose 4th term is 9 and the sum of its 6th and 13th terms is 40.

Find the 20th term of an A.P. whose 5th term is 15 and the sum of its 3rd and 8th terms is 34.

Find the sum of first 25 terms of an A.P.whose nth term is 1-4n

Find the common difference of an A.P.whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 5 and the sum of its first four terms is half the sum of the next four terms.

Find the common difference of an A.P. whose first term is 100 and the sum of whose first six terms is five times the sum of the next six terms.