question: Tim decides to light off some fireworks for the fourth of July.  He buys a package of fireworks worth $400 and another pack worth twice that much.  He gets a 20% discount on them.  He also buys a finale firework that costs $150.  How much did he spend in total?
answer: The second package was worth 400*2=$<<400*2=800>>800
  So the two packages were worth 400+800=$<<400+800=1200>>1200
  That means he got a discount of 1200*.2=$<<1200*.2=240>>240
  So the packages cost 1200-240=$<<1200-240=960>>960
  So he spent a total of 960+150=$<<960+150=1110>>1110
  #### 1110