Two cubes have their volumes are in the ratio 1:27. Find the ratio of their surface area? Choose the correct answer:
A) 1:2
B) 2:3
C) 1:9
D) 2:7
E) 3:11
Let their edges be a and b   Then, a^3 / b^3 = 1/27   (a/b)^3 = (1/3)^3   a/b = 1/3   Ratio of their surface areas = 6a^2 / 6b^2 = (a/b)^2 = 1/9 = 1:9   Answer is 1:9
<result>C</result>
Two cubes have their volumes are in the ratio 1:27. Find the ratio of their surface area?