Mom bought 3 kilograms of tomatoes, paid the salesperson 10 yuan, and got back 0.4 yuan. How much is it per kilogram of tomatoes? (solution with equation)
妈妈买了3千克番茄，付给营业员10元钱，找回0.4元，每千克番茄多少元？(用方程解答)
<gadget id="calculator">10 - 0.4</gadget>
<output>9.6</output>

<gadget id="calculator">9.6 / 3</gadget>
<output>3.2</output>

<result>3.2</result>