How many grams of hydrochloric acid solution with 18% hydrochloric acid content is needed to prepare 1000 grams of 20% hydrochloric acid solution with 18% and 23% hydrochloric acid solutions.
用盐酸含量为18%和23%的盐酸溶液配制浓度为20%的盐酸溶液1000克，需要用盐酸含量为18%的盐酸溶液多少克．
<result>600</result>