Gold is 19 times as heavy as water and copper is 9 times as heavy as water. In what ratio should these be mixed to get an alloy 18 times as heavy as water?	Pick.
A) 1:2  B) 3:2  C) 9:1  D) 5:2  E) 6:5
G = 19W   9:1 = 9W   Let 1gm of gold mixed with x gm of copper to get 1+x gm of the alloy   1gm gold + x gm copper = x+1 gm of alloy   19W+9Wx = x+1 * 18W   19+9x = 18(x+1)   x = 1/9   Ratio of gold with copper = 1:1/9 = 9:1   Answer is 9:1
<result>C</result>
Gold is 19 times as heavy as water and copper is 9 times as heavy as water. In what ratio should these be mixed to get an alloy 18 times as heavy as water?