A pesticide solution and water are formulated at a ratio of 1:1500. To prepare 750.5 kg of this pesticide, how many kg of liquid medicine is needed? (answer with ratio)
一种农药用药液与水按1：1500配制而成．要配制这种农药750.5千克，需要药液多少千克？(用比例式解答)
<gadget id="calculator">1 + 1_500</gadget>
<output>1_501</output>

<gadget id="calculator">1 / 1_501</gadget>
<output>1/1_501 = around 0.000666</output>

<gadget id="calculator">750.5 * (1/1_501)</gadget>
<output>0.5</output>

<result>0.5</result>