Gold is 10 times as heavy as water and copper is 5 times as heavy as water. In what ratio should these be mixed to get an alloy 9 times as heavy as water?	Pick
A) 3:2	B) 1:2	C) 4:1	D) 5:2	E) 4:3
G = 10W   4:1 = 5W   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   10W+5Wx = x+1 * 9W   10+5x = 9(x+1)   x = 1/4   Ratio of gold with copper = 1:1/4 = 4:1   Answer is 4:1
<result>C</result>
Gold is 10 times as heavy as water and copper is 5 times as heavy as water. In what ratio should these be mixed to get an alloy 9 times as heavy as water?