3 friends equally shared 1/2 pound of trail mix, during the hike. 
 
Total quantity of trail mix = 1/2 pound 
 
Quantity shared by each friend is 1/3 rd of the trial mix 
 = 1/3 * 1/2 pound 
 = 1/6 pound 
 
Therefore, during the hike, each friend shared 1/6 pound of the trail mix. 
 
Hope this helps ..!! 
 
Thank you :)