46) In evaluating the arithmetic expression 2*3-(4+5),using stacks to evaluate its equivalent postfix form, which of the following stack configuration is not possible?

47) Stack A has the entries a,b,c(with a on top).
Stack B is empty.An entry popped out of stack A can be printed immediately or pushed to stack B.An entry popped out of the stack B can only be printed. In this arrangement, which of the following permutations of a,b,c are not possible

48) The expression which accesses the (ij)th entry of am x n matrix stored in column major form is

49) Stack cannot be used to

50) Which of the following permutations can be obtained in the output(in the same order),using a stack assuming that the input is the sequence 1,2,3,4,5 in that order?