A company starts on January 1st with a stock of a particular material obtained by a purchase of 20 units at a cost of $14 per unit. On January 20th 40 units of the material are purchased at a cost of $15 per unit. On January 30th, production withdraws 40 units of the material from stock. The cost of the 40 units for production when reckoned on the basis of first in, a) first out is_ b) first out is_ The cost of the 40 units for production when reckoned on the basis of last in, c) The cost of the 40 units for production when reckoned on the basis of average cost is