Answer:
0.0531
Step-by-step explanation:
This is a typical Geometric Probability question.
Let X = digit 0
then X' = all other 9 digits except 0
P(X) = 0.1
P(X') = 0.9
If 0 (X) first occurs on the 7th event, that means for the 1st to 6th event would be other digits besides 0 (X'). Therefore, the probability:
P = P(1st event) × P(2nd event) × P(3rd event) × P(4th event) × P(5th event) × P(6th event) × P(7th event)
= P(X') × P(X') × P(X') × P(X') × P(X') × P(X') × P(X)
= (P(X'))⁶ × P(X)
= 0.9⁶ × 0.1
= 0.0531