If the sum of the AP 48,44,40,36,..... upto n terms is `-168` ,then the value of n is

Sum of the series 1+3+7+15+....... upto n terms.

The sum of n terms of AP is 3n^(2)+5n. and its nth term is 164. find the value of n.

Sum the series .4+.44+.444+... to n terms.

The sum of first n terms of an A.P. is 5n^(2) + 3n . If the nth term is 168, find the value of n. Also find the 20th term of the A.P.

The maximum value of the sum of the A.P 50,48,46,44,.... is

If the sum of the first 2n terms of the AP 2, 5, 8 ....is equal to the sum of first n terms of the AP 57, 59, 61, ..., then what is the value of n?

If the sum of first n terms of an AP 2,4,6, . . . 240, then the value of n is

If (3+5+7+... upto n terms )/(5+8+113... upto 10 terms )=7, then find the value of n.

If S_(n), denotes the sum of n terms of an AP, then the value of (S_(2n)-S_(n)) is equal to