Find the number of terms in the sequence is 3,7,11………,99

Find the sum to n terms of the sequence : 1,-1,1,-1,........ ,(-1)^(n+1) , ..........

Find the number of terms common to the two A.P. s : 3,7,11 , 407a n d2,9,16 , ,709.

find the 3rd term in the sequence: an =(-1)n+15n+1

Find the sum of the sequence -8, -5, -2 ,... 7

Find the number of terms in each of the following APs :- 7, 13, 19,..., 205 .

Find the sum of n terms of the following sequences: 8+88+888+……………..up to n terms.

Find the first five terms of the sequence whose n^(th) term is a_n = 2^(n + 3)

Find the first six terms of the sequence whose first term is 1 and whose (n+1)th term is obtained by adding n to the nth term.