The simple interest on a sum of money will be Tk. 600 after 10 years. If the principal is trebled after 5 years, What will be that total interest at end of the tenth year?

A Tk. 600

B Tk. 900

C Tk. 1200

D Tk. 1500

Correct Answer: Option C

Let, sum = BDT. x, Time = 10 years Then S.I = Rs.600, Rate = = (6000/x)% per annum S.I. on BDT.x for Ist five years = BDT.