To prepare a medicine, the mass ratio of medicine powder to water is 1:40. To prepare 205 kilograms of medicine, how many kilograms of medicine powder are needed
配制一种药水，药粉和水的质量比是1：40，要配制205千克的药水，需要药粉多少千克
<gadget id="calculator">1 + 40</gadget>
<output>41</output>

<gadget id="calculator">1 / 41</gadget>
<output>1/41 = around 0.02439</output>

<gadget id="calculator">205 * (1/41)</gadget>
<output>5</output>

<result>5</result>