15. Calculate how much percentage a person invest of his salary

Deepak's salary is \(₹\)40000, from which he deposits \(x\%\) amount at the rate of 6\(%\) in simple interest. If the accumulated amount for the sum deposited after 4 years was \(₹\)12500, then find the value of \(‘x’\).

 

Deepak deposits ______\(\%\) of his salary.