求助几道GWD数学 感激不尽

zccwen

1  If Antonio bought two half-gallon cartons of ice cream during a special sale, what percent of the total regular price of the two cartons did he save?

(1)   Antonio paid the regular price for the first carton and received the second carton for half the regular price.

(2)   The regular price of the ice cream Antonio bought was $4.00 per half-gallon carton.

                                                                                                                              

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.

(A)

 

2 Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m.  By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?

 

A.      k/m %

B.       (k-m) %

C.      [100(k-m)]/(100+k) %

D.      [100(k-m)]/(100+m) %

E.       [100(k-m)]/(100+k+m) %

Answer: ?D

 

3 A solid yellow stripe is to be painted in the middle of a certain highway.  If 1 gallon of paint covers an area of p square feet of highway, how many gallons of paint will be needed to paint a stripe t inches wide on a stretch of highway m miles long?  (1 mile = 5,280 feet and 1 foot = 12 inches)

 

A.     (5,280 mt) / 12p

B.     (5,280 pt) / 12m

C.     (5,280 pmt) / 12

D.     (5,280)(12m) / pt

E.      (5,280)(12p) / mt

(A)

非常感谢！

v6y4g1

2). (1+k)/(1+m) - 1

     (k-m)/(1+m)

     [(k-m)/(1+m)]*100

 100(k-m)/(100+m)          <ie: if m and k are intergers )

v6y4g1

3)( 5280 x (t/12) x m) / P

  5280*t*m/12 p 

best4380

[(k-m)/(1+m)]*100   ====>>>>>  100(k-m)/(100+m)  
how?

zccwen

谢谢，谁来解释下第一道题呢？