Question 120402
There are 10 more boys than girls in a class.  If one more girl joins the class, there will be twice as many boys as there are girls.  How many boys and how many girls are there in the class?
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Original numbers:
Let number of girls be "x", then number of boys is "x+10".
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Numbers after the change:
# of girls = x+1 ; # of boys is still "x+10"
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EQUATION:
x+10 = 2(x+1)
x+10 = 2x+2
x = 8 (original # of girls) ; x+10 = 18 (original # of boys)
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Cheers,
San H.