question: John goes to the market and buys 3 goats for $500 each and 2 cows for $1500 each.  How much money did he spend?
answer: The goats cost 3*500=$<<3*500=1500>>1500
  The cows cost 2*1500=$<<2*1500=3000>>3000
  So in total he spends 1500+3000=$<<1500+3000=4500>>4500
  #### 4500