SOLUTION: In a certain school there are twice as many girls as boys.50% of the boys and 20% of the girls do not have lunch in school. What percent of the school enrollment does have lunch in

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Question 327982: In a certain school there are twice as many girls as boys.50% of the boys and 20% of the girls do not have lunch in school. What percent of the school enrollment does have lunch in school?
A 30% B 40% C 50% D 60% E 70%

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
let boys be x
girls = 2x
..
50% of boys have lunch
80% of girls have lunch0.
0.5x+0.8*2x have lunch.
0.5x+1.6x have lunch
2.1x have lunch
..
2.1x/3x*100 is the percentage that have lunch.
0.7*100=70%