NINE CARDS ARE NUMBERED FROM 1 TO 9 RESPECTIVELY. TWO CARDS ARE DI...

1. Nine cards are numbered from 1 to 9 respectively. Two cards are distributed to

each of four children. The sum of the numbers on the two cards the children

are given is: 7 for Ann, 10 for Ben, 11 for Cathy and 12 for Don. What is the

number on the card that was not distributed?