The harrison family drove a total of 857.25 miles in three days. on the first day, they drove 298.5 miles. on the second day, they drove 338.7 miles. how many miles did they drive on the third day?

Apyramid fits exactly inside a cube. the cube and the pyramid share the same square base, and they are both exactly the same height. the volume of the cube is 66 cubic inches. what is the volume of the pyramid? explain your answer. answer asap