City X has a population 6 times as great as the population of City Y, which has a population twice as great as the population of City Z. What is the ratio of the population of City X to the population of City Z?	Answers:  A) 1:8  B) 1:4  C) 2:1  D) 4:1  E) 12:1
x= 6y, y= 2*z   X : Y , Y : Z   6 : 1 , 2 : 1   12 : 2 , 2 : 1   So, X : Z =12 : 1   (12:1)
<result>E</result>
City X has a population 6 times as great as the population of City Y, which has a population twice as great as the population of City Z. What is the ratio of the population of City X to the population of City Z?