I go 5 km East, then turn right and go 8km. Then I turn left and go 5 km and then I turn left and go 8 km. At what distance am I from the starting point?
The weights of 4 boxes are 20, 40, 60 and 90 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?