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 a 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 10?

3 4 5 6 7

to have a sum of 10 on two papers

1+9 , 2+8 , 3+7 , 4+6 only

7 is my answer worst case the first draws are (0,5,1,2,3,4,)

any additional one will give 10

EDITED BECAUSE OF TWO THINGS 1) NEVER RUSH IF U SEE A QUESTION THAT U THINKS IT IS EASY FOR U TO SOLVE ......... FATAL MISTAKE

2) WE WONT HAVE Ciceron on G day to advice you to concentrate

(though i wish i can

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