Aunt Zhang bought many apples at a price of 3 apples for 1 yuan, and sold these apples at a price of 5 apples for 2 yuan. Aunt Zhang made a net profit of 10 yuan today, how many apples did she sell?
张大妈以1元钱3个苹果的价格买进许多苹果，又以2元钱5个苹果的价格将这些苹果卖出．今天张大妈净赚10元钱，请问她卖出苹果多少个？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">10 / (1/15)</gadget>
<output>150</output>

<result>150</result>