Final answer:
The probability of choosing a Crunch bar from the bag is 15/51, which simplifies to 5/17.
Step-by-step explanation:
The student is asking about the probability of choosing a Crunch bar from a bag containing a mix of different candy bars. To find this probability, we divide the number of Crunch bars by the total number of bars. We have 15 Crunch bars and a total of 51 bars when we add up all the different types (15 + 14 + 10 + 12). Therefore, the probability of selecting a Crunch bar at random is 15/51. However, this fraction can be simplified by dividing both numerator and denominator by 3, resulting in a simplified fraction of 5/17. Although the options provided in the question seem to be incorrect as they all are 15/51, the correct probability, in reduced form, is 5/17.