Paul teaches the guitar in groups of three students. He rents a room for the guitar classes at $250 per month. He charges $30 per hour per student. Paul teaches six groups of students, and his net earnings per month are $1,910.
Part A: If each student learns guitar for the same number of hours, write an equation that can be used to calculate the number of hours each student learns guitar in a month.
Part B: How many hours did each student learn guitar each month? Show your work and justify each step of your work.