Question 990451
The concentration is in DOLLARS per POUND.  You can find a clear idea of what to do if you understand that PARTS per HUNDRED, meaning percent, is also often used as a concentration unit.


Use this video example to help understand.  You have dollars per pound instead of percents.
<a href="https://www.youtube.com/watch?v=-REjxT9KCzQ">Using just one variable for a two-part mixture problem</a>