Amachine packs at a constant rate of 2/3 of a box every 1/2 minuet. what’s is the number of boxes per minute that’s the machine packs?

For this case what we can do is the following rule of three:
 2/3 of a box > 1/2 minutes
 x of a box > 1 minute
 Clearing x we have:
 x = (1 / (1/2)) * (2/3)
 Rewriting:
 x = 2 * (2/3)
 x = 4/3
 
 the number of boxes per minute that the machine packs is:
 x = 4/3