2、某农场拟修建一批半球壳顶的圆筒形谷仓，计划每座谷仓容积为300立方米，圆筒半径不得超过3米，高度不得超过10米。半球壳顶的建筑造价为每平方米150元，圆筒仓壁的造价为每平方米120元，地坪造价为每平方米50元，求造价最小的谷仓尺寸为多少？-2, a cylindrical barn farm to be constructed in a number of hemispherical shell top, plan every seat barn volume of 300 cubic meters, the radius of the cylinder must not more than 3 m, a height of not more than 10 meters. Hemispherical shell roof of the building at a cost of 150 yuan per square meter, the cylindrical wall of the warehouse at a cost of 120 yuan per square meter, floor at a cost of 50 yuan per square meter, the cost of the minimum required number of barn size?