rectangular fish pond 20 meters wide. Due to the expansion of the road, the width of the fish pond was reduced by 5 meters and the area was reduced by 150 square meters. What is the current area of the fish pond? (two ways to answer)
一个宽20米的长方形鱼塘．因拓建公路，鱼塘的宽减少了5米，面积减少了150平方米．现在鱼塘的面积是多少？(两种方法解答)
<gadget id="calculator">150 / 5</gadget>
<output>30</output>

<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">30 * 15</gadget>
<output>450</output>

<result>450</result>