150 millimetres = 0.150 meter
To get area, divide volume by thickness
1/0.150 = 6.66 square metres
100 mmm = 0.100 meter 28 x .1 = 2.8 cubic meters
7 cement bags per 1 cubic meter of concrete......
According to Blue Circle it takes 108 bags of concrete to get a cubic meter
One ton
12L