Two friends start at the same point. A walks 3 km east, then 4 km north. B walks 4 km east, then 3 km north. The distance between them now is:

1. A ends at (3, 4) from start; B ends at (4, 3). 2. Difference vector = (4-3, 3-4) = (1, -1). 3. Distance = sqrt(1^2 + (-1)^2) = sqrt(2). 4. = 1.414 km. 5. So they are about 1.4 km apart. _Source: SSC CGL Reasoning (Direction Sense), standard PYQ patterns_