Two planes start from the same airport. A flies 50 km East. B flies 15 km North, then turns East and flies 20 km, then turns to its right and flies 15 km. Where is B with respect to A now?
14 notebooks of a class were corrected with ink pen while 22 notebooks were corrected with colour pencil. If 4 notebooks were corrected with both, what is the strength of class?