[求助]Few JJ questions - TEST tomoorw, plz help. thx

My test questions # is based on adamhhh's math material.

My test is tomorrow NOON! Your response will be greatly appreicated.  thx thx!!

214、

Q11

Of the three-digit positive integers that have no digits equal

to zero, how many have two digits that are equal to each

other and the remaining digit different from the other two?

A.    24

B.     36

C.     72

D.    144

E.     216

Answer E

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MingLiU","serif"; mso-bidi-font-family: PMingLiU; mso-font-kerning: 0pt;">No idea why is 216??

 111、問直線的斜率是否是正

A.在x軸的截距intercept和在y軸上的截距均為正

B.在x軸的截距intercept是y上截距的2倍

答：A(A) 截距有正負 (A)斜率一定是負的(B)不確定

If this Answer is A, should the follow question’s (#229) answer be D ?

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229、問斜率？但直線不過原點
        

A 在X軸截距是Y軸截距的2倍 

B 在X Y都是正截距  

答：A斜率-1/2 

nancy: Shouldn’t this be D?

227、1<=n<10,n是整數，問n值：1。n和1/n的十分位相同 2。n和1/n的百分位相同

答：A(1) n=3, 1/3=0.3333333 (2) n=3, 1/3=0.3333333  n=6, 1/6=0.16666666666

Nancy: How about n=1? Will that make the answer E instead?

152、x 是個正數。問x 距離10E-2和距離10E-3哪個近。
(1)x距離10E-2比距離10E-1近
(2) x距離10E-3比距離10E-1近

答：A

Why is this Answer A ???

227,选A 因为(1)的条件可以推出只有N=1的时候,(2)的条件可以推出n=1, 2 , 5

152 选E吧,(1)推出x<0.05 (2)推出x<0.05 ,所以选E

227.) (1)的条件 can also work when n=3, isn't it??

214:

相等的数可以是12，23，13

相等的数的数值有9种情况，所以剩下一个有8种情况

故9*8*3