A water tank is built in the shape of a circular cone with height 5 m and diameter 6 m at the top. Water is being pumped into the tank at a rate of 1.6 m min. Find the rate at which the water level is rising when the water is 2 m deep. A printed page is to contain 60 cm? of printed material with clear margins of 5 cm on each side and 3 cm on the top and bottom. Find the minimum total area of the page