Final answer:
The theoretical probability of selecting card B is 1/10.
Step-by-step explanation:
The theoretical probability of selecting card B can be found by dividing the number of times card B is selected by the total number of selections.
In this scenario, we can calculate the theoretical probability of selecting a card with B using the following formula:
Theoretical Probability = Favorable Outcomes / Total Possible Outcomes
Favorable Outcomes: We know that the card with B is selected 3 times out of 30 trials.
Total Possible Outcomes: Since each card is placed back in after each selection, there are 30 possible outcomes for each trial.
Therefore, the theoretical probability of selecting a B is:
Probability = 3 / 30
Simplifying the fraction, we get:
Probability = 0.1 or 1/10
In conclusion, the theoretical probability of selecting a card with B is 0.1 or 1/10.