To prepare a pesticide, the ratio of pesticide to water is 1:150, if there is 525kg of water, how many kilograms of pesticide is needed to prepare this pesticide.
配制一种农药，其中药与水的比为1：150，如果有水525千克，要配制这种农药，需要多少千克的药．
<gadget id="calculator">1 / 150</gadget>
<output>1/150 = around 0.006667</output>

<gadget id="calculator">525 * (1/150)</gadget>
<output>7/2 = around 3.5</output>

<result>7/2 = around 3.5</result>