If the first term of an A.P. is 3 and the sum of its first four terms is equal to one-fifth of the sum of the next four terms, then the sum of the first 20 terms is equal to (1) - 1080 (2) - 1020 (3) - 1200 (4) - 120
If the first term of an A.P. is 3 and the sum of its first four terms is equal to one-fifth of the sum of the next four terms, then the sum of the first 20 terms is equal to\\
(1) - 1080\\
(2) - 1020\\
(3) - 1200\\
(4) - 120