Tony is laying out the design for a concrete path. The path is to be L-shaped as shown in the plan. The measurements are in millimetres. 1200 6200 1200 Tony calculates that 3 cubic metres of concrete is enough for the path. He decides to use a concrete mix which has: cement 1 part sand 2 parts gravel - 3 parts How many cubic metres of gravel does Tony need? 4000