A certain sum becomes four times itself at simple interest in eight years. In how many years does it become ten times itself?  Choose the correct option: A) 24 B) 55 C) 77 D) 99 E) 01
Let the sum be Rs. x, then it becomes Rs. 4x in eight years Rs. 3x is the interest on x for eight years.   R = (100 * 3x)/(x * 8) = 300/8 %   If the sum becomes ten times itself, then interest is 9x.   The required time period = (100 * 9x)/(x * 300/8) = (100 * 9x * 8)/(x * 300) = 24 years.24nswer: 24
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A certain sum becomes four times itself at simple interest in eight years. In how many years does it become ten times itself?