38) The data structure required to check whether an expression contains balanced parenthesis is

39) The postfix form of A*B+C/D is

40) Which of the following types of expressions does not require precedence rule when evaluated

41) The five items:A,B,C,D, and E are pushed in a stack, one after the other starting from A.The stack is popped four times and each element is inserted in a queue.Then two elements are deleted from the queue and pushed back on the stack.Now one item is popped from the stack. The popped item is

42) If memory for the run-time stack is only 150 cells(words), how big can N be in Factorial(N) before encountering stack overflow