Question 1031871
There are 65 people on an airplane. Out of those 65 people there are three times as many women as there are men, ten less girls than there are women and the amount of boys is only a quarter of the amount of girls. 
How many men, women, girls and boys are on board the plane? 
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w = 3m
g = w-10
b = (1/4)g
w + m + g + b = 65
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Get it down to one variable:
m = (w/3)
g = w - 10
b = (1/4)g = (1/4)(w-10) = (w-10)/4
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Substitute to get:
w + (w/3) + w-10 + (w/4) - (10/4) = 65
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12w + 4w + 12w - 120 + 3w - 30 = 65*12
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31w = 930
w = 30 (# of women)
m = (w/3) = 10 (# of men)
g = w-10 = 20 (# of women)
b = (1/4)g = 5 (# of women)
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Cheers,
Stan H.
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