For the following APs, write the first term and the common difference:
(i) 3, 1, -1, -3, ....
(ii) -5, -1, 3, 7, ....
(iii) 13, 53, 93, 133, ....
(iv) 0.6, 1.7, 2.8, 3.9, ...

(i) 3, 1, -1, -3…
Here, first term, a = 3
Common difference, d = Second term - First term
d = 1 - 3 = -2
(ii) -5, -1, 3, 7…
Here, first term, a = -5
Common difference, d = Second term - First term
d = (-1) - (-5) = -1 + 5 = 4
(iii) 13, 53, 93, 133
Here, first term, a = 13
Common difference, d = Second term - First term
d = 53 - 13 = 40
(iv) 0.6, 1.7, 2.8, 3.9…
Here, first term, a = 0.6
Common difference, d = Second term - First term
d = 1.7 - 0.6 = 1.1