Question

If an island only residents are penguins and beans and if there’s 18 heads and 50 feet on the island how many penguins in bears

Answer 1

let p = # of penguins and b = # of bears

p + b = 18 (both animals have 1 head)

2p + 4b = 50 (bears have 4 feet while penguins have 2)

We have a system of linear equations and can solve with elimination or substitution.

Using elimination,

2(p + b = 18) -> 2p + 2b = 36

Subtract this from the other equation to get

2b = 14 -> b = 7 (7 bears)

p = 18 - b -> p = 11 (11 penguins)