The weights of 4 boxes are 30, 40, 50 and 100 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes and in a combination a box can be used only once?
Of the six members of a panel sitting in a row, A is to the right of C, but left of B. E is sitting left of C and right of D, who is sitting to the right of F. Find the members sitting at the two ends of the row.