GWD 29-22

guyuan0126

thanks a lot!

sweetjiong

第一次是3块m个人分，第二次是1块m-4个人分，个么：

3/m + 1/(m-4),通分一下得到E

guyuan0126

Four extra-large sandwiches of exactly the same size were ordered for m students, where m > 4.  Three of the sandwiches were evenly divided among the students.  Since 4 students did not want any of the fourth sandwich, it was evenly divided among the remaining students.  If Carol ate one piece from each of the four sandwiches, the amount of sandwich that she ate would be what fraction of a whole extra-large sandwich?

A. (m+4)/m/(m-4)

B.(2m-4)/m/(m-4)

C.(4m-4)/m/(m-4)

D.(4m-8)/m/(m-4)

E.(4m-12)/m/(m-4)

答案:E

想不通怎么得到答案的？