How much would it cost driving 300 miles at 25 mpg 4.00 a gallon?

```

Cost = (Distance / MPG) * Cost per gallon

```

In this case, we have:

```

Distance = 300 miles

MPG = 25 mpg

Cost per gallon = $4.00

```

Plugging these values into the formula, we get:

```

Cost = (300 miles / 25 mpg) * $4.00 = $48.00

```

Therefore, it would cost $48.00 to drive 300 miles at 25 mpg with gas priced at $4.00 per gallon.