Hotel AB parking space

Method 1: ① If there is an empty parking space between car A and car B, there are 15A22 = 10 methods;

(2) If there are two empty parking spaces between car A and car B, there are 8 methods of C14A22;

(3) If there are three empty parking spaces between A and B, there are six methods: c13a22 =;

(4) If there are four empty parking spaces between car A and car B, there are A2A2 = 4 methods;

⑤ If there are five empty parking spaces between car A and car B, there is a method of A22=2.

To sum up, * * has 10+8+6+4+2=30 methods.

Method 2: If two cars, A and B, are parked in two of the seven parking spaces respectively, there are A27=42 parking methods, among which the adjacent method of AB is C 16A22= 12, so there are 42- 12=30 different parking methods that need at least one empty parking space between A and B. 。

So choose C.