小象乐乐准备在一块长20米、宽10米的土地上盖一间房子。要盖房子就得先挖好地基,于是乐乐找来了山羊伯伯:“伯伯,我要在这块土地的四周挖一条宽1米、深1米的沟以做成地基,你能帮我算一下要挖多少立方米的土吗?”山羊伯伯算了一下,说:“要挖56立方米的土!”乐乐想:如果一个人一天挖8立方米土的话,七个人 Elephant Lele prepares to build a house on a piece of land 20 meters long and 10 meters wide. To build a house, you have to dig the ground first, so Lele has taken the goat, Uncle: “Uncle, I want to dig around this piece of land for a width of 1 meter and a depth of 1 meter to make the foundation. You can help I figure how much cubic meters of earth to dig it? ”Goat uncle forget, said:“ to dig 56 cubic meters of soil! ”Lele think: if a person digs 8 cubic meters of soil a day, then seven personal