You have $30,000 in credit. Can you buy the $25,000 Miata?
Yes. You have enough credit for the car.
Recall the problem:
You would like to buy a new $25,000 red Miata sports car. You can pay in cash, or you can buy it on credit.
It turns out that you actually have $240 on hand and are a student with a major in philosophy. The credit manager is unwilling to extend any credit to you.