The ratio of the arithmetic mean of two numbers to one of the numbers is 5:8. What is the ratio of the smaller number to the larger number? Select:
A) 1 : 8	B) 1 : 6	C) 1 : 5	D) 1 : 4	E) 1 : 3

Rationale: "for two numbers , the arithmetic mean is the middle of the two numbers . the ratio of the mean to the larger number is 5 : 8 , thus the smaller number must have a ratio of 2 . the ratio of the smaller number to the larger number is 2 : 8 = 1 : 4 . the answer is d ."
Answer: D