mariag0113
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- Sep 17, 2011
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1.)the ratio of boys to girls in art class is 3:5. ther are 12 boys in the class . how many girls are in the class?
help me now its my homework due tomooro ??!!!!!!
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1.)the ratio of boys to girls in art class is 3:5. ther are 12 boys in the class . how many girls are in the class?
Dunno if this is best way to do it but just my way xD
3 boys / 3 = 1
5 girls / 3 = 1.666666667
12boys * 1.6666667 = 20 girls
then u have 12 boys 20 girls
12/20 is 0.6
3/5 =0.6
Hello, mariag0113!
Another approach . . .
More algebraic, but much longer.
We are told: .\(\displaystyle \text{boys}:\text{girls} \:=\:3:5\)
This means: .\(\displaystyle \begin{Bmatrix}\text{boys} \,=\, 3n \\ \text{girls} \,=\, 5n \end{Bmatrix}\;\text{ for some integer }n\)
We are told: .\(\displaystyle 3n = 12\)
. . . .Hence: .. \(\displaystyle n = 4\)
Therefore: .\(\displaystyle \text{girls} \,=\,5n \,=\,5(4) \,=\,20\)
Another approach . . .
More algebraic, but much longer.
We are told: .\(\displaystyle \text{boys}:\text{girls} \:=\:3:5\)
This means: .\(\displaystyle \begin{Bmatrix}\text{boys} \,=\, 3n \\ \text{girls} \,=\, 5n \end{Bmatrix}\;\text{ for some integer }n\)
We are told: .\(\displaystyle 3n = 12\)
. . . .Hence: .. \(\displaystyle n = 4\)
Therefore: .\(\displaystyle \text{girls} \,=\,5n \,=\,5(4) \,=\,20\)