At what rate percent per annum will a sum of money double in 7 years.  Choose the correct answer:
A) 12.5% B) 13.5% C) 14.2% D) 14.5% E) 21.5%
Let principal = P, Then, S.I.=P and Time=8 years   Rate = [(100 x P)/ (P x 8)]% = 14.2% per annum. Answer: 14.2%
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At what rate percent per annum will a sum of money double in 7 years.