Students passing College Computer Science Principles might have been passed Quiz 1 in Unit: Digital Information.

In this quiz, there is a question asking about possible count of license plates in a country as a binary format:

HOW MANY UNIQUE LICENSE PLATES ARE THERE IN 7 BITS?

The acceptable answer is 2^7 = 128. But all we know that actually no car can take zero (0000000) as a license plate so the answer must be (2^7) - 1 = 128 - 1 = 127.

Can anyone explain? Am I right?