You walk into a barn and see a collection of pigs (P), chickens (C) and horses (H). You notice that there are 480 legs in total. The number of chickens is twice the number of horses. The number of pigs is twice the number of chickens. Compute the number of pigs.

The provided info is: The number of chickens (C) is twice the number of horses (H). The number of pigs (P) is twice the number of chickens. There are 480 legs in total. So, \begin{equation} C = 2H \end{equation} \begin{equation} P = 2C \end{equation} We know that Chickens have two legs Horses and pigs have four legs So, \begin{equation} 2C + 4H + 4P = 480 \end{equation} We can rewrite the equations as follows: \begin{equation} C = \frac{P}{2} \end{equation} \begin{equation} H = \frac{C}{2} = \frac{P}{4} \end{equation} So, \begin{equation} 2 \frac{P}{2} + 4 \frac{P}{4} + 4P = 480 \end{equation} \begin{equation} 6P = 480 \end{equation} \begin{equation} P = 80 \end{equation}

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You walk into a barn and see a collection of pigs (P), chickens (C) and horses (H). You notice that there are 480 legs in total.

The number of chickens is twice the number of horses.
The number of pigs is twice the number of chickens.

Compute the number of pigs.

The provided info is:

The number of chickens (C) is twice the number of horses (H).
The number of pigs (P) is twice the number of chickens.
There are 480 legs in total.

So, \begin{equation} C = 2H \end{equation} \begin{equation} P = 2C \end{equation} We know that

Chickens have two legs
Horses and pigs have four legs

So, \begin{equation} 2C + 4H + 4P = 480 \end{equation} We can rewrite the equations as follows: \begin{equation} C = \frac{P}{2} \end{equation} \begin{equation} H = \frac{C}{2} = \frac{P}{4} \end{equation} So, \begin{equation} 2 \frac{P}{2} + 4 \frac{P}{4} + 4P = 480 \end{equation} \begin{equation} 6P = 480 \end{equation} \begin{equation} P = 80 \end{equation}

Correct Answer: 80

Python scratchpad

# Run Python right here in your browser
def two_sum(nums, target):
    seen = {}
    for i, n in enumerate(nums):
        if target - n in seen:
            return [seen[target - n], i]
        seen[n] = i
    return []

print(two_sum([2, 7, 11, 15], 9))  # [0, 1]

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Number of Pigs

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