Answer as a fraction = 1/720
Answer in decimal form (approximate) = 0.001388
Answer in percent form (approximate) = 0.1388%
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Explanation:
Let A = 1 to indicate the number of ways to get the names to line up in alphabetical order.
There are B = 6*5*4*3*2*1 = 720 different ways to arrange the six people. Notice how I started at 6 and counted my way down to 1, multiplying all along the way. This can be shortened to factorial notation to say 6! = 720. Or you could use the nPr permutation formula to get the same result (use n = 6 and r = 6).
Once you have the values of A and B, we form the fraction A/B = 1/720 which is the probability of getting the names in alphabetical order.
If you need the answer in decimal form, then use your calculator to find
1/720 = 0.001388
which converts over to 0.1388%
