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?

Question

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

Answer 1

i am confused about this problem and would like some help. thank you x.x

Answer 2

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.

Answer 3

thank you, ms. sue! that's what i thought it was but i was confused. :)

Answer 4

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)

Answer 5

You're welcome, bubbie.

Answer 6

nonzero digits = 1-9

Answer 7

1/6 or A