If the length of the sides of two cubes are in the ratio 5:1, what is the ratio of their total surface area?
Choose the correct choice from the following choices
A) 5 : 1
B) 10 : 1
C) 25 : 1
D) 50 : 1
E) 150 : 1

Rationale: "let x be the length of the small cube ' s side . the total surface area of the small cube is 6 x ^ 2 . the total surface area of the large cube is 6 ( 5 x ) ^ 2 = 150 x ^ 2 . the ratio of surface areas is 25 : 1 . the answer is c ."
Answer: C