Put 400ml of water into a cuboid cup with a bottom area of 60cm**2, and then put a potato into the cup (the potato is completely submerged in the water). At this time, the water depth is 7.5cm. What is the volume of the potato in cm**3.
在一个底面积是60cm**2的长方体杯子中装入400ml水，再把一个马铃薯装入杯中(马铃薯被水完全浸没)，这时水深7.5cm，马铃薯的体积是多少cm**3．
<gadget id="calculator">60 * 7.5</gadget>
<output>450</output>

<gadget id="calculator">450 - 400</gadget>
<output>50</output>

<result>50</result>