question: John buys 10 bottles of scotch for a total cost of $600.  He also buys twice as many bottles of cognac that cost 50% more per bottle.  How much does he spend on everything?
answer: The scotch cost $600/10=$<<600/10=60>>60 each
  He bought 10*2=<<10*2=20>>20 bottles of cognac
  Each bottle cost .5*60=$<<.5*60=30>>30 more than the scotch
  So they cost $60+$30=$<<60+30=90>>90
  That means he spent $90*20=$<<90*20=1800>>1800 on the cognac
  So he spent a total of $600+$1800=$<<600+1800=2400>>2400
  #### 2400