TT 2-9,20,32

dlmmdajgal

Q9:

What was the price at which a merchant sold a certain appliance?

(1)   The merchant’s gross profit on the appliance was 20 percent of the price at which the merchant sold the appliance.

(2)   The price at which the merchant sold the appliance was $50 more than the merchant’s cost of the appliance.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

Ans is C, but (2) never game the cost of appliance? or is it 50+x=20%?

Q20:

A collection of 36 cards consists of 4 sets of 9 cards each.  The 9 cards in each set are numbered 1 through 9.  If one card has been removed from the collection, what is the number on that card?

(1)
                  The units digit of the sum of the numbers on the remaining 35 cards is 6.

(2)
              The sum of the numbers on the remaining 35 cards is 176.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

I have no idea how this works..... very confused....

Q32:

What is the remainder when the two digit, positive integer x is divided by 3?

(1)
              The sum of the digits of x is 5.

(2)
              The remainder when x is divided by 9 is 5.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.          

(1) 14, 23,32,41,50 are all possible, but the ramainder is always 2, why is that?

(2) if it can be divided by 9, then by 3 is known?

毕业后饮酒过度，杀死无数脑细胞。不知道大家如何看这些数学题，我平均一套要2.5小时.

dianecarton

第一题，我觉得把(2)里面的merchant's cost理解成merchant's price就可以了，跟（1）构成二元一次方程组，所以C

第二题，选D

（１）拿走了一张card，剩下cards的和的个位是6,所有cards的总和是180,很明显拿走的那张是4 单独充分

（２）剩下35张cards的和是176,所有的cards的和是180,所以拿走的那张是4　　单独充分

第三题，选D

（1）推出该两位数可能为14，41，32，23，余数都是2  单独充分

（2）X=9m+5=3（3m+1)+2 余数为2   单独充分

dlmmdajgal

9m+5=3（3m+1)+2为什么写成这个形式？我还是不太明白

前两题明白了，谢谢呀~~~