Question 468942
<pre>
We add their rates to get their combined rate:

360{{{packages/hour}}} + 140{{{packages/hour}}} = 500{{{packages/hour}}}

1 hour is 60 minutes, so the problem is now:

If they can seal 500 packages in 60 minutes, how many
minutes will it take them to seal 700 packages?

We set up the proportion: 

500 packages     700 packages
------------  = --------------
 60 minutes        x minutes

Cross multiply

         500x = 42000

            x = {{{42000/500}}} = 84 minutes


Edwin</pre>