Let t, h, b represent the weighs of tail, head, and body, respectively.
t = 4 . . . . given
h = t + b/2 . . . . the head weighs as much as the tail and half the body
b/2 = h + t . . . . half the body weighs as much as the head and tail
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Substituting for b/2 in the second equation using the expression in the third equation, we have
... h = t + (h + t)
Subtracting h from both sides gives
... 0 = 2t . . . . . . in contradiction to the initial statement about tail weight.
Conclusion: there's no solution to the problem given here.
