Each of the integers from 0 to 9, inclusive, is written on a separate slip of blank paper and the ten slips are dropped into hat. If the slips are then drawn one at a time without replacement, how many must be drawn to ensure that the numbers on two of the slips drawn will have a sum of 11?
Pick: A) 3 B) 4 C) 5 D) 6 E) 7
i'm not sure i got the question right, if it is what i think it is, then 7 should be the right answer   0,1,2,3,4,5, will not have 2 slip sum of 10, add another (either 6,7,8 or 9) and we'll have a pair with sum 10   Ans:7
<result>E</result>
Each of the integers from 0 to 9, inclusive, is written on a separate slip of blank paper and the ten slips are dropped into hat. If the slips are then drawn one at a time without replacement, how many must be drawn to ensure that the numbers on two of the slips drawn will have a sum of 11?