GRE考试选择题精炼
A breeder has ten birds:
Kind Male Female
Goldfinches H J, K
Lovebirds M N
Parakeets Q, R, S T, W
The breeder exhibits pairs of birds consisting of one male and one female of the same kind. At most two pairs can be exhibited at a time; the remaining birds must be distributed between two cages. The breeder is constrained by the following conditions:
Neither cage can contain more than four birds. Any two birds that are both of the same sex and of the same kind as each other cannot be caged together. Whenever either J or W is exhibited, S cannot be exhibited.
(13). Which one of the following is a possible assignment of the birds?
First Cage Second Cage Exhibition
(A) H, M, N J, K, S Q, R, T, W
(B) K, M, Q N, R, W H, J, S, T
(C) K, Q, S R, T, W H, J, M, N
(D) H, J, M, R K, N, S, W Q, T
(E) H, J, M, R, W K, N, S Q, T, W
(14). Which one of the following lists two pairs of birds that the breeder can exhibit at the same time?
(A) H and J; M and N
(B) H and J; S and T
(C) H and K; M and N
(D) H and K; R and W
(E) M and N; S and W
(15). If Q and R are among the birds that are assigned to the cages, then it must be true that
(A) H is exhibited
(B) K is exhibited
(C) N is exhibited
(D) J is assigned to one of the cages
(E) T is assigned to one of the cages
