Mix a pesticide with water to make a potion, the ratio of pesticide to water is (1/150). The existing pesticide is 4 kg, how much water should be added?
把一种农药和水混合配制成药水，农药和水的比值是(1/150)．现有农药4千克，要加多少千克水？
<gadget id="calculator">1 / 150</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">4 / (1/150)</gadget>
<output>600</output>

<result>600</result>