(i) 3,1,–1,–3,…

(ii) –5,–1,3,7,…

(iii) 1/3, 5/3, 9/3, 13/3,…

(iv) 0.6, 1.7, 2.8, 3.9,…

**Solution:**

**(i) 3, 1, – 1, – 3 …**

First term, a = 3

Common difference, d = Second term – First term

⇒ 1 – 3 = -2

⇒ d = -2

**(ii) – 5, – 1, 3, 7 …**

First term, a = -5

Common difference, d = Second term – First term

⇒ ( – 1)-( – 5) = – 1+5 = 4

⇒ d = 4

**(iii) 1/3, 5/3, 9/3, 13/3 ….**

First term, a = 1/3

Common difference, d = Second term – First term

⇒ 5/3 – 1/3 = 4/3

⇒ d = 4/3

**(iv) 0.6, 1.7, 2.8, 3.9 …**

First term, a = 0.6

Common difference, d = Second term – First term

⇒ 1.7 – 0.6 = 1.1

⇒ d = 1.1