Question: I'm completely lost with this math problem: A fruit vendor bought 50 watermelons for $80. He sold all of them at a profit of 25%. How much was each watermelon sold?
Can you give me a hand?
Answer: 
The fruit vendor's profit for the 50 watermelons was $80 x 25/100 = $20.
So, he was able to sell them all for $80 + $20 = $100.
Thus, the vendor sold each watermelon for $100/$50 = $2 each.