Question

A man is appointed in a job with a monthly salary of certain amount and a fixed amount of annual increment. If his salary was Rs 19,800 per month at the end of the first month after 3 years of service and Rs 23,400 per month at the end of the first month after 9 years of service, find his starting salary and his annual increment. (Use matrix inversion method to solve the problem.)

Answer 1

Let his monthly salary be Rs x and his annual increment be Rs y 

Given x + 3y = 19800 and x + 9y = 23400 

Writing the above equations in matrix form, we get

x = Rs 18000 and y = Rs 600 

(i.e) monthly salary = Rs 18000 and annual increment = Rs 600