<PRE><B>Question 539499</B>
 the ratio of boys to girls in history class is 4 to 5. How many girls are in the class if there ar 12 boys in the class? explain
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4 to 5 is the same as 4x to 5x
where 
# of boys = 4x 
and
# of girls = 5x
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4x = 12
x = 3
---
# of girls = 5x = 5*3 = 15

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Cheers,
Stan H.
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