a droplet of oil drops onto the surface of a bowl of water. The surface that the oil covers is twice the surface that it covers a
minute ago. If it takes 4 minutes to cover the whole surface of the bowl of water, when does it cover 1/4th of the surface of the bowl?
Each and every person in this world are having "constant mind"...DIFFERENTIATE others mind and INTEGRATE urs.MATHEMATICS SIMPLY MAKES YOU UNSTOPPABLE !!!