A paper boy cycles 10 km East, then turns South and cycles 3 km, then turns West and cycles 6 km, then turns to his right and cycles 3 km. Where is he now with reference to his 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 90, 30, 40 and 60 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?