Find the sums given below :

(i) 101 + 99 + 97 +.........+ 47
(ii) 5 + 8 + 11 +.........+ 185
(iii) 2 + 4 + 6 +.........+ 200
(iv) 3 + 11 + 19 +.........+ 803

98.

Find the sum of the following A.P.s : (i) 36, 31,.........to 10 terms.
(ii) a + b, a – b, a – 3b..........to 22 terms.
(iii) (x – y)², (x² + y²), (a + y)²,........to n terms.

In an A .P.
(i) given a = 5, d = 3, T_n = 50, find n and S_n.
(ii) given a = 6, d = 4, T_n = 50 find n and S_n.
(iii) given a = 7, d = 6, T_n = 43, find n and S_n.