Subba Rao started work in 1995 at an annual salary of rupay 5000 and received an increment of rupay 200 each year. In which year did his income reach ` 7000?

Starting salary = a = Rs 5000 annual increment (common difference) = d = Rs 200
Let, after n years, his salary become Rs 7000.
Therefore, a_n = 7000
⇒ a + (n -1)d = 7000
⇒ 5000 + (n – 1)(200) = 7000
⇒ (n -1)(200) = 2000
⇒ n – 1 = 10 ⇒ n = 11
Hence, in 11th year his salary become Rs 7000.