数学题求解。谢谢！

40 boys and 28 girls stand in a circle, hand in hand, all facing inwards. Exactly 18 boys give their right hand to a girl. How many boys give their left hand to a girl?

 

A) 18               B) 9                 C) 28               D) 14               E) 20

所有跟帖： 

• 18 -holymolycow- ♂ (955 bytes) () 10/09/2016 postreply 14:43:37

• 不用考虑那么复杂。 -money4ivy- ♀ (173 bytes) () 10/09/2016 postreply 14:59:32

• 不能理解啊，好像你是对的。 -一九得九- ♀ (0 bytes) () 10/09/2016 postreply 15:29:43

• 牛！看懂了，你是从BOY 算，我从GIRL 算 -一九得九- ♀ (0 bytes) () 10/09/2016 postreply 15:01:10

• 哈哈，亲，像我这样用尽洪荒之力攻克数学就为BSO，不用等到老年就走火入魔了 -一九得九- ♀ (0 bytes) () 10/09/2016 postreply 15:22:42

• BSO -一九得九- ♀ (35 bytes) () 10/09/2016 postreply 15:30:44

• 也是18 -一九得九- ♀ (246 bytes) () 10/09/2016 postreply 14:47:55

• 哈哈，希望成技校妈 -一九得九- ♀ (0 bytes) () 10/09/2016 postreply 15:32:45

• This is more a logic reasoning than math -Derrick_Liu- ♂ (529 bytes) () 10/09/2016 postreply 15:03:24

• 谢谢大家！ -ssll- ♀ (0 bytes) () 10/09/2016 postreply 15:27:59