Hi All,
We're told that City X has a population 4 TIMES as great as the population of City Y, which has a population TWICE as great as the population of City Z. We're asked for the ratio of the population of City X to the population of City Z. Based on the design of this question - and the design of the answer choices, we can get the correct answer without doing much math at all.
To start, we know that the population of City X is 4 TIMES as great as that of City Y and City Y's population is GREATER than that of City Z. When comparing City X's population to City Z's, we know that City X's population has to be MORE than 4 TIMES greater than City Z's... and there's only one answer that would account for that type of difference..
Final Answer: E
GMAT assassins aren't born, they're made,
Rich