求A的出生日期

A的出生日期係12號
B的出生日期係26號

Let the birth of A is c (Wed)
so that the birth of B is c+7/14/21/28(wed)

c+c+7/14/21/28=38
2c+7/14/21/28=38
For their birth must be a interger,so 7/21 is impossie.
2c+14/28=38
if the number is 28,
2c+28=38
c=5
but if A's birth is 5th
B's birth is 5+28=33th
so A's birth is in 5th is impossible.
if the number is 14
2c+14=38
c=12
if A's birth is 12th,so B's birth is 12+14=26th
So 12th is the answer.

A=10 B=18
(如果1號係星期一的話)

應該答唔到


1年入面既每1個10月既星期3都唔1樣日子.

例如今年既10月 星期3有1.8.15.22.29
上年既10月 星期3有3.10.17.24.31
下年既10月 星期3有7.14.21.28

由此可見,冇可能計到

2008-02-21 21:59:47 補充：
樓上個位,唔通你係年年試既!?