The simple interest on a sum of money will be Rs. 600 after 10 years.If the principal is trebled after 5 years,what will be the total interest at the end of the tenth year ?	Choose the correct choice from the following answers.
A) Rs. 600	B) Rs. 900	C) 1200 rupees	D) Rs. 1500	E) None
Solution   22.22   Let the sum be Rs. x. Now, S.I. = Rs. 600,T = 10 years.   Rate = % = (100x600/X x 10)% =(6000/X)%   S.I. for first 5 years = Rs.(X x 5 x 6000/X x 100) = Rs. 300.   S.I. for first 5 years = Rs. (3X x 5 x 6000/X x 100)= Rs. 900.   ∴ Total interest = Rs. 1200.   Answer 1200 rupees
<result>C</result>
The simple interest on a sum of money will be Rs. 600 after 10 years.If the principal is trebled after 5 years,what will be the total interest at the end of the tenth year ?