I already know the answer... it's 14. However, I do not know how to get this right answer. Please show me step by step. I have a test tomorrow and there will be a question somewhat like this one on it. Thank you so much!!

Question

1. A physical education class has three times as many girls as boys. During a class basketball game, the girls average 18 points each, and the class as a whole averages 17 points per person. How many points does each boy score on average?

Answer 1

If the boys average n points each, then just add up the total points

g = 3b
18g + nb = 17(g+b)
54b + nb = 17(3b+b)
54b + nb = 68b
54+n = 68
n = 14