A brine is prepared by mixing salt and water in a mass ratio of 1:30. How many grams of salt should be added to 45 grams of water?
一种盐水是由盐和水按1：30的质量比配制而成的．45克水中需要加入盐多少克．
<gadget id="calculator">45 / 30 / 1</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>