India's Largest Education Online Store: StudyNeeds.com | For questions call: 011-456-293-45 | Log In Here | Create Free Account
Answers (1)

-
Let the initial value of salary = I
Let the first rate of increase = r% and the second rate of increase = 2r%
So , after first increment the salary becomes I(1+r/100)
After second increment the final salary becomes = I(1+r/100)(I+2r/100)
But that is equal to 15/8I
I(1+r/100)(1+ 2r/100) = (15/8)I
Let r/100 = x
This reduces to the quadratic equation :
16x2 + 24x - 7 = 0
Also x has to be positive , so x = 1/4
r/100 = 1/4 or r = 25%