Question 4 (20 marks) a. Let E be the solid bounded by the surfaces = = y, y=1-x and = =0: 0.6) 021 0.8 0.6 ? =0 (xy-plane) 04 0.5 02 The y-coordinate of the centre of mass is given by the triple integral 15 Evaluate this integral. (10 marks) Hint: Determine the limits of integration first. Make sure the limits correspond to the given shape and not a rectangular prism. You do not have to show where the integral came from. just evaluate the integral