boat goes upstream with a speed of 32 kilometers per hour and a water speed of 2 kilometers per hour. How many kilometers can the boat travel in 4 hours?
一艘船逆流而上，船速为每小时32千米，水速是每小时2千米，这艘船4小时能行多少千米．
<gadget id="calculator">32 - 2</gadget>
<output>30</output>

<gadget id="calculator">30 * 4</gadget>
<output>120</output>

<result>120</result>