In a certain code language, 'x' represents '+', '÷' represents 'x', '-' represents '÷' and '+' represents '-'. Find out the answer to the following question.
The weights of 4 boxes are 40, 70, 80 and 50 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?
A woman in a shopping complex walks 150 m East, then she turns North and walks 180 m, then she turns West and walks 70 m, then she turns to her left and walks 180 m. Where is she now with reference to her starting position?