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

is this probability?

anonymous · Answer

$$P(A) ={The~Number~Of~Ways~Event~A~Can~Occur\over The~total~number~Of~Possible~Outcomes}$$

anonymous · Answer

the event can occur 3 times, I'm just having a hard time finding all the possible outcomes

anonymous · Answer

total number of possible outcomes, i would think to be 7 since there are 7 slips of paper

anonymous · Answer

reading this could possibly help you http://www.mathgoodies.com/lessons/vol6/intro_probability.html

kropot72 · Answer

There are 2 outcomes adding up to 6:
2 + 4 = 6
1 +5 = 6
P(2 and 4) =1/7 * 1/6 = 1/42
P(1 and 5) = 1/7 * 1/6 = 1/42
P((2 and 4) or P(1 and 5) = 1/42 + 1/42 = 1/21
Probability that the sum does not add up to 6 = 1 - 1/21 = 20/21
The odds are:
 P(sum not 6): P(sum is 6) = 20/21 : 1/21 = 20 : 1