At what rate percent per annum will a sum of money double in 16 years  Select:
A) 6 ¼ % p.a
B) 6 % p.a
C) 8¼ % p.a
D) 3 ¼ % p.a
E) 7 ¼ % p.a
Let principal = P. Then, S.l. = P and T = 16 yrs.   Rate = (100 x P)/(P*16)% = 6 ¼ % p.a   Answer is 6 % p.a.
<result>B</result>
At what rate percent per annum will a sum of money double in 16 years