Rugby and ballet
What is the average weight of five ballet dancers and ten rugby players?
Problem
The total mass of five rugby players is $425 \; \text{kg}$.
The average (mean) mass of ten ballet dancers is $40 \; \text{kg}$.
What is the average mass of all fifteen people?
Student Solutions
The mass of the $10$ ballet dancers is
The average mass of all $15$ people is