It took 4 hours 34 minutes for one cannibal to remain. It took 5 cannibals, 2/5 hours to eat the first victim, four cannibals 2/4 hours to devour the second, three cannibals 2/3 hours for the third, two cannibals 2/2 hours for the fourth and one cannibal 2/1 hours for the fifth. One could argue that stomach contents increase a cannibal's edible volume when he is the victim. However, if the further interpretation is granted that these contents also turn a cannibal as consumer into more than one cannibal, the original solution is restored!