A potion is prepared by mixing medicine and water in a ratio of 2:45. The existing medicine is 140 grams, how many grams of water need to be added?
一种药水是把药和水按2：45的比例配制成的．现有药140克，需要加水多少克？
<gadget id="calculator">2 / 45</gadget>
<output>2/45 = around 0.044444</output>

<gadget id="calculator">140 / (2/45)</gadget>
<output>3_150</output>

<result>3_150</result>