L _ T
M
=
M _ S S _ _ N _ R Y
_ N D
C
=
C _ N N _ B _ L .
T H _ S
_ S
H _ W
T H _ Y
C R _ S S
T H _
R _ V _ R :
M , C
→
←
M
C , C
→
←
C
M , M
→
←
M , C
M , M
→
N _ W ,
T H _ R _
_ R _
3
M _ S S _ _ N _ R _ _ S
_ N D
1
C _ N N _ B _ L
_ N
T H _
_ T H _ R
S _ D _
_ F
T H _
R _ V _ R .
T H _ S
C _ N N _ B _ L
C _ N
F _ T C H
T H _
_ T H _ R
2
C _ N N _ B _ L S
_ N _
B Y
_ N _ Clue
LET M = MISSIONARY AND C = CANNIBAL. THIS IS HOW THEY CROSS THE RIVER: M,C → ← M C,C → ← C M,M → ← M,C M,M → NOW, THERE ARE 3 MISSIONARIES AND 1 CANNIBAL ON THE OTHER SIDE OF THE RIVER. THIS CANNIBAL CAN FETCH THE OTHER 2 CANNIBALS ONE BY ONE FIRST, TAKE THE SHEEP ACROSS, COME BACK AND THEN TAKE THE BUNDLE OF GRASS. SINCE THE SHEEP WILL EAT THE GRASS IF LEFT UNATTENDED, TAKE THE SHEEP BACK ACROSS AND THEN TAKE THE LION ACROSS. THEN TAKE THE SHEEP BACK ACROSS AND THEY ARE ALL UNHARMED INLESS SOME ONE CAN TELL ME A WAY THAT 2 PRISONERS, AT SOME POINT, DON'T OUT NUMBER THE GUARDS WHETHER THEY ARE JUST DROPPING OFF AND STILL IN THE BOAT OR ACTUALLY ON LAND (BECAUSE EVEN IF THEY ARE JUST DROPPING OFF AND REMAIN IN THE BOAT THEY ARE STILL ON THE OTHER SIDE OF THE RIVER) I CONCLUDE THIS TO BE IMPOSSIBLE. PLEASE LET ME KNOW AN ALTERNATIVE IF YOU FIGURE ONE OUT BECAUSE I'M STUMPED. THANKS TAKE THE FOX OVER, RETURN WITH NOTHING. GO OVER WITH ONE CHICKEN, RETURN WITH THE FOX. GO OVER WITH THE SECOND CHICKEN, RETURN WITH NOTHING. FINALLY, TAKE THE FOX OVER. OR LET: MAN = M FOX = F CHICKEN1 = C1 CHICKEN2 = C2 THIS IS HOW THEY CROSS THE RIVER: M,F → ← M M,C1 → ← M,F M,C2 → ← M M,F →