A brine is a mixture of salt and water in a ratio of 9:1. How many kilograms of water are needed to prepare 180 kilograms of this brine?
一种盐水是用盐和水按照1：9配成的．要配制这种盐水180千克，需要水多少千克？
<gadget id="calculator">1 + 9</gadget>
<output>10</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">180 * (9/10)</gadget>
<output>162</output>

<result>162</result>