8. (10 points) Nine cards are labeled with the numbers $2,3,4,5,6,7,8,9,10$ (they cannot be read upside down). Four people, Jia, Yi, Bing, and Ding, each draw two of these cards.
Jia says: "The two numbers I got are coprime, because they are consecutive"
Yi says: "The two numbers I got are not coprime, and they are not in a multiple relationship"
Bing says: "The two numbers I got are both composite, but they are coprime"
Ding says: "The two numbers I got are in a multiple relationship, and they are not coprime"

If all four people are telling the truth, then the number on the remaining card is $\qquad$
【Solution】Solution: According to Bing saying: "The two numbers I got are both composite numbers, but they are coprime," it can be deduced that they are two of $4, 8, 9$, and 10. The two numbers Bing drew are 9 and one of $4, 8, 10$; According to Yi saying: "The two numbers I got are not coprime, and they are not in a multiple relationship," it can be deduced that 2 is definitely not included, so they can only be two of $4, 6, 8, 10$, which are 4 and $6, 4$ and $10, 6$ and $8, 6$ and $10, 8$ and 10; First, assume that the two numbers Bing drew are 9 and 4; The two numbers Yi drew are 8 and 6, leaving 2, 3, 5, 7, 10. At this point, first satisfy Jia saying: "The two numbers I got are coprime because they are adjacent," the numbers that satisfy this condition are 2 and 3; Then, 5, 7, 10 remain, among which the numbers that satisfy Ding saying: "The two numbers I got are in a multiple relationship, and they are not coprime" are 5 and 10, so the last remaining number is 7.

Answer: The number on the remaining card is 7.
Therefore, the answer is: 7.