Harpreet rides to her aunt's farm at 12 km/h and returns at 18 km/h. The two rides together take 5 hours. How far is the farm?

Explanation

1. 01

   $\frac{d}{12} + \frac{d}{18} = 5$.

2. 02

   LCM 36: $\frac{3d + 2d}{36} = 5$, so $5d = 180$.

3. 03

   $d = 36$ km.