Please assist in answering all questions below

The materials specifications for product A show that one completed unit is made from the following raw materials: Standard composition for one completed product: Material J 2kg@2.00 per kg=4.00 Material K2 kg@ 3.00 per kg =6.00 Material L4 kg@1.50 per kg=6.00 Materials purchased and issued to produce 100 units of product A: Material J210 kg @1.90 per kg Material K205 kg@ 2.80 per kg Material L 395kg@1.60 per kg Required Calculate the following variances in respect of materials: (a) Mix variance (b) Yield variance