Geometry

Question Analysis
This question involves combining data from two frequency tables to calculate the probability of a single event.
The main focus is on correctly adding up the frequencies of the desired category (rock music) from both tables and also finding the total combined frequency of all students in both classes to calculate the probability.

Key Concept Explanation
The probability of an event is calculated as .
When combining data from multiple sources, we sum up the relevant frequencies and the total frequencies across all the sources.

Step-by-Step Solution
First, find the total number of students in Class A: