请教OG DS 273, 240 and 231

wlee2001

先谢谢各位看我的POST和回答我的问题．

273.  If x and y are nonzero integers, is x^y < y^x?

(1) x=y^2

(2) y>2

Answer: C

不明白解释里的推理, 为什么y^x = y^2?

240.  If x and y are positive integers such that x = 8y+12, what is the greatest common divisor of x and y?

(1) x=12u, where u is an integer

(2) y=12z, where z is an integer

Answer: B

不明白解释说的 Since 12=x-8y, any common divisor of x and y must be a divisor of 12.  Therefore no integer greater than 12 is a common divisor of x and y...

231.  Of the 4800 voters who voted for or against Resolution K, 1800 were Democrats and 3000 were Republicans.  What was the total number of female voters who voted for Resolution K?

(1) 3/4 of the Democrats and 2/3 of the Repulbicans voted for Resolution K.

(2) 1/3 of the Democrats who voted for Resolution K and 1/2 of the Republicans who voted for Resolution K were females.

Answer: C

我觉得题目中没说没有人弃权.如果有的活(1)和(2)加起来也得不出结论.

wlee2001

Can someone give me some help.  I will take my exam soon.

Thank you thank you than you!!!!!!!!!!!!!!!!!!!!!!!!!

titatita

ding

273我也不明白呀