2011GRE考试选择题精炼(1)

　　2014gre数学选择题精炼

　　Petworld has exactly fourteen animals that are kept in four separate cages according to the following conditions:

　　Each cage contains exactly two, four, or six animals. Any cage containing a gerbil also contains at least one hamster; any cage containing a hamster also contains at least one gerbil. Any cage containing a lizard also contains at least one snake; any cage containing a snake also contains at least one lizard. Neither cage Y nor cage Z contains a gerbil. Neither cage W nor cage X contains a lizard.

　　. Which one of the following could be a complete and accurate list of the animals kept in cages W and Y?

　　 W: one gerbil and one hamster; Y: two lizards and two snakes

　　 W: one gerbil and two hamsters; Y: one lizard and three snakes

　　 W: two gerbils and two hamsters; Y: one lizard and four snakes

　　 W: two gerbils and two hamsters; Y: three lizards and one snake

　　 W: two gerbils and two lizards; Y: two hamsters and two snakes

　　. If there are exactly two hamsters in cage W and the number of gerbils in cage X is equal to the number of snakes in cage Y, then the number of snakes in cage Z must be exactly

　　 one

　　 two

　　 three

　　 four

　　 five

　　. If cage Z contains exactly twice as many lizards as cage Y, which one of the following can be true?

　　 cage Y contains exactly two lizards.

　　 Cage Y contains exactly two snakes.

　　 Cage Y contains exactly four animals.

　　 Cage Z contains exactly three snakes.

　　 Cage Z contains exactly two animals.

　　. If the number of animals in cage W is equal to the number of animals in cage Z, then which one of the following can be true?

　　 Cage W contains exactly six animals.

　　 Cage X contains exactly six animals.

　　 Cage Y contains exactly one snake.

　　 Cage Y contains exactly three snakes.

　　 Cage Z contains exactly four snakes.

　　. If cage W contains six animals, which one of the following must be true?

　　 Cage W contains two gerbils.

　　 Cage X contains four animals.

　　 Cage Z contains two snakes.

　　 The number of snakes in cage Y is equal to the number of lizards in cage Y.

　　 The number of snakes in cage Z is equal to the number of lizards in cage Z.

　　. At most, how many snakes can occupy cage Y at any one time?

　　 one

　　 two

　　 three

　　 four

　　 five

　　KEYS: ADCDED