A truck travels 36 km North, then it turns West and travels 9 km, then it turns South and travels 50 km, then it turns to its left and travels 9 km. Where is it now with reference to its starting position?
In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
The weights of 4 boxes are 20, 40, 50 and 30 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?