Teacher Sun painted the walls of a room, and used 1.5 kilograms of paint to paint 3 square meters. The walls of this room are 78 square meters in total. How many kilograms of paint are needed to paint this room?
孙老师粉刷一间屋子的墙壁，粉刷3平方米用了涂料1.5千克．这间屋子墙壁共78平方米，粉刷完这间屋子需要多少千克涂料？
<gadget id="calculator">1.5 / 3</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 * 78</gadget>
<output>39</output>

<result>39</result>