Question

A locker combination has four nonzero digits. If no digit can be repeated and the first three digits are 1-2-3, what is the probability that the fourth digit is 4?

A. 1/6
B. 1/7
C. 1/8
D. 1/9

Answers

bubbie
i am confused about this problem and would like some help. thank you x.x
Ms. Sue
Since the combination has already used 1, 2, and 3. Then the 4th digit must be either 4, 5, 6, 7, 8, or 9.

So the probability must 1 out of 6 or 1/6.

bubbie
thank you, ms. sue! that's what i thought it was but i was confused. :)
PsyDAG
With your data, I am confused too. How many total numbers are there?

Since the first 3 numbers cannot be repeated, the answer = 1/(total-3)
Ms. Sue
You're welcome, bubbie.
bubbie
nonzero digits = 1-9
emma
1/6 or A

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