Question 612572
If an island’s only residents are penguins and
bears, and if there are 15 heads and 36 feet on the
island, how many penguins and how many bears
are on the island? 
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Heads: p + b = 36
Feet: 2p +4b = 36
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Multiply thru the Heads equation by 2:
2p + 2b = 72
2p + 4b = 36
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Subtract and solve for "b":
2b = 36
b = 18 (# of bears)
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solve for "P":
p + b = 36
p + 18 = 36
p = 18 (# of penquins)
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Cheers,
Stan H.