If rupee one produces rupees nine over a period of 40 years, find the rate of simple interest?\nOptions:\n(A) 22 1/7%\n(B) 22 7/2%\n(C) 29 1/2%\n(D) 22 1/2%\n(E) 22 1/3%
Let's be accurate as possible and think first.
(D)
9 = (1*40*R)/100\nR = 22 1/2 %.

The answer is (D)