[問題]GWD24-3

[magic]

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.
答案是C
我絕得是Eㄟ
可以請大大門交一下ㄇ

[navywhite0425]

題目是說有r 跟b 兩種chips
r可以拿x分
b可以拿y分
x>y>0
求5x+3y/8=?

以上為題目

1)r+b的average points=x+y/2=5
so x+y=10 不充分
2)告訴你5x+3y/8 的解為整數 這也沒啥用= =

合併
小弟的作法是
硬算
因為x>y>0 且 x+y=10
若x=9 y=1 代入5x+3y/8 會得解為6 且為整數
接下來就繼續代
會發現只有這組可以
記得x一定要 >y 唷!!

so it's "C"

[magic]

感謝^^