solution:公仔箱論壇* u& j. P) `4 I" x
% a0 [" n+ u1 k- m' D5.39.217.77:88981st and 2nd lady go over: 2 mins taken4 V& K+ Q7 b+ C' k/ J
1st lady walk back: 1 mins taken( w n4 Q: f. W
3rd and 4th lady go over: 10 mins taken5 `6 u- y3 U& Z0 n2 O
2nd lady walk back: 2 mins taken5.39.217.77:8898, B2 j7 \& G6 u
1st and 2nd lady walk back: 2 mins taken
& B+ Y; h+ n6 ^& N; j8 K公仔箱論壇
# j: o6 N7 s! d% `In total : 17 mins taken!!! Solved!! |