question: Mike decides he wants to replace his movie collection with digital versions.  He has 600 movies.  A third of the movies are in various series and he knows he can get those for only $6 of the cost of a normal movie by just buying the series together.  40% of the remaining movies are older movies which are $5.  How much does replacing the movies cost if a normal movie costs $10?
answer: There are 600/3=<<600/3=200>>200 movies in series
  So he pays 200*6=$<<200*6=1200>>1200
  He has 600-200=<<600-200=400>>400 movies not in series
  400*.4=<<400*.4=160>>160 movies are old
  So those cost 160*5=$<<160*5=800>>800
  400-160=<<400-160=240>>240 movies are neither old nor in series
  They cost 240*10=$<<240*10=2400>>2400
  So the total cost is 1200+800+2400=$<<1200+800+2400=4400>>4400
  #### 4400