$3 、$ A and B each hold 7 cards, on which the numbers $1 、 2 、 3 、 4 、 5 、 6 、 7$ are written respectively. If both draw one card, what is the probability that the sum of the numbers on the two cards is 8?
【Analysis】The total number of possibilities when each of the two people draws one card is $7 \times 7=49$. Among these, the combinations where the sum of the numbers is 8 are: $1+7,2$ $+6,3+5,4+4,5+3,6+2,7+1$, totaling 7 possible combinations. Therefore, the probability that the sum of the numbers on the two cards is 8 is one-seventh.