求教GWD一道数学题

adasuying2004

3
in a certain game played with red chips and blue chips, each red chip has a point value of X and each blue chip has a point value of Y, where X>Y and X and Y are positive integers. If a player has 5 red chips and 3 blue chips, what is the average (arithmetic mean ) point value of the 8 chips that the player has?
(1)    The average point value of one red chip and one blue chip is 5.
(2)    The average point value of the 8 chips that the player has is an integer.
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?    Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient
?    Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient
?    BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
?    EACH statement ALONE is sufficient
?    Statements (1) and (2) TOGETHER are NOT sufficient
Answer
为C。为啥可算？

camelo777

由条件1可知 x=3,y=2或x=4,y=1，有两种可能不充分
条件二，只知道8个chips的平均数是整数，不充分

1+2， 只有当x=3,y=2时，8个chips的平均数才是整数，所以1+2充分，所以选C