The difference between compound interest and simple interest on a certain sum of money for 3 years at 16 \(\frac{2}{3}\)% p.a. is Rs. 57. The sum of money is:

Rs. 216 Rs. 108 Rs. 432 Rs. 648

Rs. 648

16 \(\frac{2}{3}\)% = \(\frac{1}{6}\) Here, Difference = 19R = 57 1R = 3 Principal = 216R = 216 × 3 = Rs.648