An AP consists of 37 terms. The sum of the three middle most terms is 225 and the sum of the last three terms is 429. Find the AP

An AP consists of 45 terms. The sum of the three middle most terms is 546 and the sum of the last three terms is 1050. Find the AP.

An AP consists of 23 terms. If the sum of the three terms in the middle is 141 and the sum of the last three terms is 261, then the first term is

An AP consists of 23 terms. If the sum of the three terms of in the middle is 141 and the sum of the last three terms is 261 , then the first term is

An A.P. consists of 23 terms. If the sum of the three terms Is the middle is 141 and the sum of the last three terms is 261, then the first is

An A.P. consists of n terms. If the sum of its first three terms is x and the sum of the last three terms is y, then show that, the sum of all the terms of the A.P. is (n)/(6)(x+y) .

A finite AP has 21 terms . The sum of 10th, 11th and 12th term is 129 and the sum of its last three terms is 237 . Find the AP.