邮局和图书馆相距 360 m。它们位于阿里（Ali）家和纳尔逊（Nelson）家之间，如下图所示。邮局正好处于阿里家和纳尔逊家的正中间。 一天，阿里和纳尔逊同时从各自的家里出发，慢跑前往图书馆。他们在图书馆相遇。纳尔逊的慢跑速度为 85 m/min，而阿里的慢跑速度比纳尔逊快 40 m/min。

1. Calculate the difference in distance jogged by Ali and Nelson

Let the distance from the post office to either house be $d$ metres.
Distance Ali jogged $= d + 360$
Distance Nelson jogged $= d - 360$
Difference in distance $= (d + 360) - (d - 360) = 720$ m

1. Determine the difference in distance travelled by Ali and Nelson

Let the distance from the post office to either house be $d$.
Distance Ali jogged = $d + 360$
Distance Nelson jogged = $d - 360$
Difference in distance = $(d + 360) - (d - 360) = 720$ m

2. Calculate the time taken for the journey

Difference in speed = $40$ m/min
Time taken = $\frac{\text{Difference in distance}}{\text{Difference in speed}} = \frac{720}{40} = 18$ min

3. Calculate the distance Nelson jogged

Distance Nelson jogged = Speed $\times$ Time = $85 \times 18 = 1530$ m