The total mass of 1 packet of sugar and 1 packet of flour is 230g .The total mass of 1 packet of sugar and 1 packet of cocoa powder is 185g .The total mass of 3 packets of sugar,5 packets of flour and a packet of cocoa powder is 1005g.
(a) Find the mass of 1 packet of flour .
(a) Find the difference between the mass of 1 packet of sugar and 1 packet of cocoa powder.