The fruit shop shipped 20 boxes each of apples and bananas. Apples are 25kg per box and bananas are 18kg per box. How many kilograms are bananas less than apples?
水果店运来苹果、香蕉各20箱．苹果每箱25千克，香蕉每箱18千克．香蕉比苹果少多少千克？
<gadget id="calculator">25 - 18</gadget>
<output>7</output>

<gadget id="calculator">7 * 20</gadget>
<output>140</output>

<result>140</result>