A potion for spraying fruit trees, the mass ratio of pesticide to water is 1:150. Now there are 3 kilograms of pesticides. How many kilograms of water need to be added.
一种喷洒果树的药水，农药和水的质量比是1：150．现在有3千克农药．需要加多少千克水．
<gadget id="calculator">1 / 150</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">3 / (1/150)</gadget>
<output>450</output>

<result>450</result>