The simple interest on a sum of money will be Rs.1200 after 10 years. If the principal is trebled after 5 years what will be the total interest at the end of the tenth year?	Options:  A) 8981  B) 3799  C) 1200  D) 2400  E) 1732
P --- 10 ---- 1200   P --- 5 ----- 600   3P --- 5 ----- 1800   ------   =&gt; 2400   Answer: 2400
<result>D</result>
The simple interest on a sum of money will be Rs.1200 after 10 years. If the principal is trebled after 5 years what will be the total interest at the end of the tenth year?