In test question 1 it is given C/S ratio is 30% and in answers you calculated Selling Price by dividing variable cost by 70% (I guess which is 100% – 30%) , so can you explain us how u arrive at this step , I mean what have you done to the formula “total contribution = C/S ration X Sales revenue” to reach “S.P = V.C / (100% – C/S ratio) ”