9. (10 points) In order to reduce urban traffic congestion, a city plans to pilot a new traffic restriction rule starting from January 1, 2014. The rule states that vehicles with license plate numbers ending in 1 or 6 are restricted on Mondays and Tuesdays, those ending in 2 or 7 on Tuesdays and Wednesdays, those ending in 3 or 8 on Wednesdays and Thursdays, those ending in 4 or 9 on Thursdays and Fridays, and those ending in 5 or 0 on Fridays and Mondays. There are no restrictions on Saturdays and Sundays. Due to the Spring Festival on January 31, there will be no restrictions on January 30 and January 31. It is known that January 1, 2014, is a Wednesday and is restricted. Therefore, in January 2014, the group of license plate numbers with the fewest days allowed to travel is ( ).
A. 1, 6
B. 2, 7
C. 4, 9
D. 5, 0
【Solution】Solution: According to the problem, we know:
January has 31 days. Since January 1 is a Wednesday, there are 5 Wednesdays, 5 Thursdays, and 5 Fridays, and 4 Mondays and 4 Tuesdays in January. Among them, January 30 is a Thursday, and January 31 is a Friday.
Therefore, we only need to consider Wednesdays. On Wednesdays, vehicles with license plate numbers ending in 2 or 7 and 3 or 8 are restricted.
Hence, the answer is: B.
9. (10 points) In order to reduce urban traffic congestion, a city plans to pilot a new traffic restriction rule starting from January 1, 2014. The rule states that vehicles with license plate numbers ending in $1$ and $6$ are restricted on Mondays and Tuesdays, those ending in $2$ and $7$ on Tuesdays and Wednesdays, those ending in $3$ and $8$ on Wednesdays and Thursdays, those ending in $4$ and $9$ on Thursdays and Fridays, and those ending in $5$ and $0$ on Fridays and Mondays. Saturdays and Sundays are unrestricted. Due to the Spring Festival on January 31, January 30 and January 31 are also unrestricted. Given that January 1, 2014, is a Wednesday and restricted, which group of license plate numbers has the fewest days they can travel in January 2014?
A. 1,6
B. $2, 7$
C. 4,9
D. 5,0