To determine the number of inches per foot, we can solve the equation \(4y = 48r\) given that there are 48 inches in 4 feet.
Here, \(y\) represents the number of inches per foot, and \(r\) represents the number of feet. If we set \(r = 1\) (for 1 foot), the equation becomes:
\[ 4y = 48 \cdot 1 \]
This simplifies to:
\[ 4y = 48 \]
Now, we can solve for \(y\) by dividing both sides by 4:
\[ y = \frac{48}{4} = 12 \]
Thus, the number of inches per foot is \(12\).
Therefore, there are 12 inches in a foot.