3. On the table, there are 20 cards numbered from 1 to 20. Each time, Xiao Ming takes out 2 cards, with the requirement that one card's number is 2 more than twice the number of the other card. What is the maximum number of cards Xiao Ming can take out?
(A) 12
(B) 14
(C) 16
(D) 18
【Answer】A
【Question Type】Multiple, Enumeration
【Analysis】Due to the relationship of being 2 times more than 2, only two of 1, 4, 10 can be taken, only two of 2, 6, 14 can be taken, and only two of 3, 8, 18 can be taken. That is, at least 3 numbers cannot be taken here, and 11, 13, 15, 17, 19 do not satisfy the relationship of being 2 times more than 2, and thus cannot be taken either. In total, at least 8 numbers cannot be taken. Taking 12 numbers is the maximum situation. One possible enumeration of the maximum situation: $1, 4$; $2, 6$; $3, 8$; $5, 12$; $7, 16$; $9, 20$. This results in the maximum of 12 numbers being taken.