Jim drives $60 \mathrm{~km}$ south, $40 \mathrm{~km}$ west, $20 \mathrm{~km}$ north, and $10 \mathrm{~km}$ east. What is the distance from his starting point to his finishing point?
(A) $30 \mathrm{~km}$
(B) $50 \mathrm{~km}$
(C) $40 \mathrm{~km}$
(D) $70 \mathrm{~km}$
(E) $35 \mathrm{~km}$
Jim drives $60 \mathrm{~km}$ south, $40 \mathrm{~km}$ west, $20 \mathrm{~km}$ north, and $10 \mathrm{~km}$ east. What is the distance from his starting point to his finishing point?
(A) $30 \mathrm{~km}$
(B) $50 \mathrm{~km}$
(C) $40 \mathrm{~km}$
(D) $70 \mathrm{~km}$
(E) $35 \mathrm{~km}$

## Solution

We can see that Jim's finishing point $F$ is $40 \mathrm{~km}$ south and $30 \mathrm{~km}$ west of his starting point, $S$.

By Pythagoras, $A E^{2}=30^{2}+40^{2}$

$$
\begin{aligned}
A E^{2} & =2500 \\
A E & =50
\end{aligned}
$$

The distance from his starting point to his end point is 50 $\mathrm{km}$.

![](https://cdn.mathpix.com/cropped/2024_04_20_748fdafcde2a47412608g-432.jpg?height=455&width=422&top_left_y=819&top_left_x=1296)

ANSWER: (B)