WAEC Mathematics 2018 Paper

Concept:Resolve the $20$ cm distance into its north-south component using the given bearing.Explanation:A bearing of $300^\circ$ from $x$ to $y$ means $y$ is $60^\circ$ west of north from $x$.So the angle between the line $XY$ and the north direction is $60^\circ$.The north-south component of the distance $XY = 20$ cm is given by:$20 \cos 60^\circ$Since $\cos 60^\circ = 0.5$,$20 \times 0.5 = 10$ cm.This means $y$ is $10$ cm north of $x$.Therefore, $x$ is $10$ cm south of $y$.Answer:The correct answer is $10$ cm, which is Option A.