A certain sum becomes three times itself at simple interest in five years. the sum become 1200 after 9 year.calculate the principal amount.
Options
A) 250  B) 260.86  C) 288.6  D) 265.66  E) 280
Let the sum be Rs. x, then it becomes Rs. 3x in five years Rs. 2x is the interest on x for five years.   R = (100 * 2x)/(x * 5) = 40 %   s.i=p*r*t/100=x*40*9/100=3.6x   x+3.6x=1200=4.6x=1200,x=1200/4.6=260.86   ANSWER:260.86
<result>B</result>
A certain sum becomes three times itself at simple interest in five years. the sum become 1200 after 9 year.calculate the principal amount.