cuboid-shaped fish tank is 50 cm long, 20 cm wide, and 60 cm high when measured from the inside. Water is poured into the fish tank, and the water surface is 15 cm away from the mouth of the tank. How many liters of water was injected?
一只长方体形状的鱼缸，从里面量长50厘米，宽20厘米，高60厘米，向鱼缸里放水，水面距缸口15厘米．求注入了多少升水？
<gadget id="calculator">60 - 15</gadget>
<output>45</output>

<gadget id="calculator">45 / 1_000</gadget>
<output>9/200 = around 0.045</output>

<gadget id="calculator">50 * 20 * (9/200)</gadget>
<output>45</output>

<result>45</result>