For a certain experiment, if we expect to get a red marble twelve times in 60 trials, what is the theoretical probability of getting a red marble? 1/12 1/10 1/5 1/4

1/5

Step-by-step explanation:

You expect to get 12 red marbles out of 60 trials.

So, you expect to get a red marbles 12/60 of the times.

We can simplify that 12/60 to 1/5, which is a choice of answers. :-)

We assume here you correctly assume your probability level when you did your forecast of 12/60.  And either you're picking from a small pool and re-insert the marble, or you have a very large amount of marbles (at least 60).