Juan and his brother Carlos are selling lemonade. For each gallon they make it costs $3 for lemons and $2 for sugar. They sell each glass for $0.50 and get 20 glasses per gallon. If they made $25 in profit, how much did they spend on lemons?
Each gallon sells for a total of $10 because 20 x .5 = 
<gadget id="calculator">20*.5</gadget>
<output>10</output>
10.
Each gallon costs $5 to make because 3 + 2 = 
<gadget id="calculator">5</gadget>
<output>5</output>
5.
They make $5 off each gallon because 10 - 5 = 
<gadget id="calculator">10-5</gadget>
<output>5</output>
5.
They made and sold 5 gallons because 25 / 5 = 
<gadget id="calculator">25/5</gadget>
<output>5</output>
5.
They spent $15 on lemons because 5 x 3 = 
<gadget id="calculator">5*3</gadget>
<output>15</output>
15.

<result>15</result>