Solution:

Assume that the number of balls with a digit marked as zero in the experiment of four balls drawn at the same time is .

The trial is a Bernoulli trial because the balls are drawn with replacement, as can be seen.

Probability of a ball drawn from the bag to be marked as digit

It can be clearly observed that has a binomial distribution with and

Thus,

Thus, , where

Probability of no ball marked with zero among the 4 balls