Let the cost of each of the first three tires be \( x \). Since the fourth tire is $5, we can set up the following equation for the total cost:
\[ 3x + 5 = 237.50 \]
Now, we can solve for \( x \):
- Subtract 5 from both sides:
\[ 3x = 237.50 - 5 \]
\[ 3x = 232.50 \]
- Now, divide by 3:
\[ x = \frac{232.50}{3} \]
\[ x = 77.50 \]
So, the cost of each of the first three tires is $77.50. Therefore, the correct answer is:
$77.50