It is a kind of pesticide, which is made up of liquid medicine and water according to the ratio of 1:1500. There is 3kg of liquid medicine, how much water is needed to prepare it?
一种农药，用药液和水按1：1500配制而成．现有3㎏药液，需要多少㎏的水来配制？
<gadget id="calculator">1 / 1_500</gadget>
<output>1/1_500 = around 0.000667</output>

<gadget id="calculator">3 / (1/1_500)</gadget>
<output>4_500</output>

<result>4_500</result>