A mixture for concrete is made up of 105 kg of cement, 252kg of sand and 273 kg of gravel. Given that the mass of cement: the mass of sand: the mass of gravel = 1: (2x y): (x 2y) (a) write down two different equations in x and y. Simplify your equations. (b) Hence solve these two equations for the value of x and for the value of y. Give each value as a simplified fraction.
