question: A fruit vendor bought 50 watermelons for $80. He sold all of them at a profit of 25%. How much was each watermelon sold?
answer: The fruit vendor's profit for the 50 watermelons was $80 x 25/100 = $<<80*25/100=20>>20.
  So, he was able to sell them all for $80 + $20 = $<<80+20=100>>100.
  Thus, the vendor sold each watermelon for $100/$50 = $<<100/50=2>>2 each.
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