The normal scrap loss for four successive operations is 5%, 3%, 15% and 10% respectively. How many units should be started through in order to finish with 1,200 pieces? Find: a) The total machine time needed if the operation times are 3, 6, 4, and 5 minutes, respectively. b) The total cost if the cost per unit for each successive operation is $2, $5, $3, and $1, respectively.