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 7 times as heavy as water?	Choices
A) 3:2  B) 1:2  C) 3:1  D) 5:2  E) 2:3
G = 10W   C = 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 * 7W   10+5x = 7(x+1)   x = 3/2   Ratio of gold with copper = 1:3/2 = 2:3   Answer is 2:3
<result>E</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 7 times as heavy as water?