Gold is 19 times as heavy as water and copper is 9 times heavy. In what ratio must these metals be mixed so that the mixture may be 15 times as heavy as water?	Pick one.
A) 2 : 3 B) 3 : 2 C) 1 : 3 D) 2 : 1 E) None of these
? Required ratio = 6?4 = 3 : 2   Answer 3 : 2
<result>B</result>
Gold is 19 times as heavy as water and copper is 9 times heavy. In what ratio must these metals be mixed so that the mixture may be 15 times as heavy as water?