There is an alloy, the ratio of copper and zinc is 19:2, and now 8 grams of zinc are added, and the mass of the new alloy is 176 grams. How many grams of copper are there in the original alloy?
有一块合金，铜和锌的比是19：2，现在又加入了8克锌，新的合金的质量为176克．求原来的合金中铜有多少克？
<gadget id="calculator">176 - 8</gadget>
<output>168</output>

<gadget id="calculator">19 + 2</gadget>
<output>21</output>

<gadget id="calculator">19 / 21</gadget>
<output>19/21 = around 0.904762</output>

<gadget id="calculator">168 * (19/21)</gadget>
<output>152</output>

<result>152</result>