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Stanley’s bicycle lock has 4 dials, each with digits from 0 to 9. What is the probability that someone could guess his combination on the first try by randomly selecting a number from 0 to 9 four times?

 

(the answer i got was  1/6561)

 Jan 6, 2021
 #1
avatar+285 
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The number of digits on each dial is 10 and they are independent of each

other (mutually exclusive) so the number of different combinations is ....

==> 10 x 10 x 10 x 10 = 10,000

So, the probability of guessing the combination is 1 / 10,000 = 0.0001

 Jan 6, 2021
 #2
avatar+32 
+1

That's actually the answer I see in the answer key but would I put 10 as the denominator and not 9?

Kadjaye  Jan 6, 2021
 #3
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0

Yes because 0 to 9 has 10 is 0,1,2,3,4,5,6,7,8,9 so 10

 Jan 6, 2021
 #4
avatar+32 
+1

ok tysm!

Kadjaye  Jan 6, 2021

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