文学城论坛
+A-

70%

eyehalfopen 2010-04-27 10:03:54 ( reads)

Assume A, B, C, D, E, F, G born in April
Same day with A: AB AC AD AE AF AG, 1/30 chance for each combination
Similarly:
BC BD BE BF BG 1/30
.
.
.
FG 1/30
Total: 21/30 = 70%

跟帖(0)