Answer: Hello there!
I think the table is missing, but none the less, let's discuss this exercise.
Here we have a random number generator, that generates numbers between 0 and 9 (10 digits in total)
A random number generator generates this all these numbers with the same probability, and in the generator is ideal, a number generator does not depend on the number generated just before, so you could think this as a 10 side dice.
Now you have 7 of this equally possible 10 numbers that simulate that the train departure in time, then you have a 7/10 probability that the train departs in time (or a 70%)
and there are 3 numbers that simulate that the train is not in time, this represents a 30% in the simulation.
Then, in this case, you need to use the random number generator or a table of randomly generated numbers, and associate the numbers between 0 and 6 to an on-time departure and the numbers between 7 and 9 for a not on-time departure, and the results that you expect to see is that in almost the 70% of the cases the train departs in time, and in 30% not.