看不明白的一道数学题目！

ubcsong

A certain college has a total of 400 seniors, each majoring in exactly one of six subjects. A minimum of 20 seniors major in each of the six subjects. If three-quarters of the seniors major in one of four subjects, what is the greatest possible number of seniors majoring in one of the other two subjects?
   [A]100
    80
   [C] 60
   [D] 50
   [E] 20

alvin

E.20

tongxun

alvin: Could you explain this question in detail?

ubcsong

我就是不明白题目的意思，是PRINCENTON的原题。答案是A

ubcsong

SORRY，是B

melissalin

同意 B。剩下的100人，分成20（满足最少的要求）， 80（即为最多）.

猫猫头

真奇怪，如果按照题目的意思的话，应该是400*1/4-20*4=20呀～～～

lisaislisa

agree B
3/4 in one of four subjects , leaving 1/4*400=100 in the other two subjects
since each should has more than 20 seniors
the max number of one is 80 while the other is 20

^^

lisaislisa

btw , to kitten
your new pic is charming!! ^^

猫猫头

可是这100应该是包括5门的呀，而且不是说每门至少有20人吗？？？

tanx~^_^