A certain sum of money is invested and compounded annually. That sum increases to 4 times, in 4 years. In how many years, the sum increases to 16 times the principle amount?
Pure mathematics is the world's best game. It is more absorbing than chess, more of a gamble than poker, and lasts longer than Monopoly. It's free. It can be played anywhere - Archimedes did it in a bathtub.
Richard J. Trudeau, Dots and Lines
MATHEMATICS is not a magic but it involves "LOGIC"