19. Explain the following concept with reference to overheads, with suitable example : a. Classification b. Allocation c. Apportionment d. Absorption e. Under and over absorption 20.Define budgetary control and state its advantages and disadvantages. 21.Define Marginal Cost. Discuss the importance of classifying expenses into variable and fixed 22.What do you understand by P/V ratio? Discuss the importance of P/V ratio and state how P/V ratio can be improved ? 23.Explain in brief all functional Budgets? Which functional budgets are most commonly used by the management ? 24. What are the advantages arising out of the budgetary control system? What do you think are the essentials of an effective budgetary control system ? 25. Distinguish between standard costing and budgetary control