Concept:Direction sense uses coordinate movement: East is +x, West is −x, and South is −y.Explanation:Let the starting point be (0,0).After cycling 7 km East, position is (7,0).After cycling 12 km South, position is (7,−12).After cycling 7 km West, position is (0,−12).He is facing West; a left turn makes him face South.After cycling 10 km South, final position is (0,−22).So, he is 22 km South of the starting point.
