The average weight of all male stars in a movie is 71.2kg, whereas the average weight of all female stars is 50.8kg. If the mean weight of all male and female stars is 60kg, find the ratio of male stars to female stars acting in the movie.
+129849 Let x be the number of male stars
Let y be the number of female stars
So we have that
71.2x + 50.8 y
_____________ = 60 multiply both sides by x + y
x + y
71.2x + 50.8y = 60 (x + y)
71.2 x + 50.8 y = 60x + 60y subtract 60x, 50.8 y from both sides
11.2 x = 9.2 y divide both sides by 11.2 , y
x 9.2 92
__ = ___ = ____ = ratio of males / females
y 11.2 112
