For 5 rooms of students, Ms. Deutsch will need:
- 20 parent volunteers (4 per room x 5 rooms) to help students get on and off stage
- 20 parent volunteers (4 per room x 5 rooms) to assist with each room of students
Therefore, she will need a total of 40 parent volunteers in all.
To find out how many backstage rooms there were on the day of the recital:
- Subtract the number of parent volunteers helping with rooms of students (20) from the total number of parent volunteers used (12): 12 - 20 = -8
- Since this doesn't make sense as a positive value, we can conclude that there must have been an error in the scenario and it is not possible to determine the number of backstage rooms based on this information.
Using a variable for the number of rooms of students:
- Let r be the number of rooms of students.
- Ms. Deutsch will need 4r parent volunteers to help students get on and off stage.
- Ms. Deutsch will need 4r parent volunteers to assist with each room of students.
- Therefore, in all, she will need 8r parent volunteers.