Seven slips of paper marked with the numbers 1, 2, 3, 4, 5, 6, and 7 are placed in a box and mixed well. Two are drawn without replacement. What are the odds that the sum of the numbers on the two slips is not 6?

Question

anonymous · Answer

whats the formula?

anonymous · Answer

4/7 my best guess. 
1+5=6 
2+4=6
So 1, 5, 2, 4

anonymous · Answer

careful here, you are asked for odds not probability

anonymous · Answer

A

19 to 2
B

21 to 2
C

9 to 1
D

19 to 1

anonymous · Answer

these are the options. thats why im confused

jim_thompson5910 · Answer

draw a 6 by 6 table

write the numbers 1 through 6 in the row and column headers

cross out the cells that run along the main diagonal...this is because you can't pick the same number twice (remember there's no replacements)

anonymous · Answer

it is the ratio of the number of way to get not six to the number of ways to get six

skullpatrol · Answer

@Studykid2016  Do you know how probability is related to odds?

jim_thompson5910 · Answer

oh wait, not 6 by 6, 7 by 7

my bad

but the same idea applies

anonymous · Answer

maybe easier to compute the number of ways to choose 2 out of 7 as a first step, that is compute$\binom{7}{2}$ then subtract off the number of ways to get a total of 6 
then subtract the number of way to get

jim_thompson5910 · Answer

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