Question

A man is 3m to the north of a certain point. Another is 4m to the east of the same point. The first man moves further north a distance of 9m and second a distance of 9m west. The displacement them now is

Answer 1

take the point as origin
and net dicerction of person a in north direction is 3+9
person b in south direction is
9-4(minus because 9 and 4 are in opppsite direction.
use pythagoras theorem.
$\sqrt{12 {}^{2} + 5 {}^{2} } = 13$