SOLUTION: Locker comb The numbers of the lock is 0 to 39 with 3 combinations. ??? 1. How many combination are possible on ur locker 2. what is the probability that choosing a combination

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Question 616992: Locker comb
The numbers of the lock is 0 to 39 with 3 combinations.
??? 1. How many combination are possible on ur locker
2. what is the probability that choosing a combination at random would work to open ur locker
3. suppose u remember one of the numb is 14 what is the prob to open the locker
4 if u remember that the 1st numb is one digit the 2nd numb is in the teens and the last is in the thirties
5 what is the prob that u can open the locker?
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
Locker comb
The numbers of the lock is 0 to 39 with 3 combinations.
???
1. How many combinations are possible on your locker?::: 40C3 = 9880
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2. what is the probability that choosing a combination at random would work to open your locker?::: 1/9880
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3. suppose u remember one of the numb is 14 what is the prob to open the locker
Ans:
# of ways to succeed:
3 ways to place the 14
39C2 = 741 ways to pick the other 2 numbers
2 way to place the other 2 numbers
---Total # of ways to succeed: 3*741*2 = 4446
Probability of opening if one # is know: 4446/9880 =
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4 if u remember that the 1st numb is one digit the 2nd numb is in the teens and the last is in the thirties
# of ways to succeed: 10*10*10 = 1000
Prob = 1000/9880
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5 what is the prob that u can open the locker?
Under wha condition?
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Cheers,
Stan H.