Question

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

Answer 1

Given: Salary of Subba Rao in 1995 = Rs. 5000 

Annual increment = Rs. 200 

i.e., His salary increases by Rs. 200 every year.

Clearly 5000, 5200, 5400, forms an A.P in which a = 5000 and d = 200. 

Now suppose that his salary reached Rs. 7000 after x – years. 

i.e., a_n = 7000 

But, a_n = a + (n – 1)d 

7000 = 5000 + (n – 1)200

⇒ 7000 – 5000 = (n – 1)200 

⇒ n – 1 = 2000/200 = 10 

⇒ n = 10 + 1 

∴ In 11^th year his salary reached Rs. 7000.