b: # of boys
g: # of girls
kymberlee17: thier are 357 seniors in harris high school
b+g=357
kymberlee17: the ratio of boys to girls is 7:10
b/g=7/10
b+g=357
b/g=7/10 <=> b=g*7/10
(g*7/10)+g=357
g*(7/10+1)=357
g=357/(7/10+10/10)
g=357/(17/10)
g=357*(10/17)=210 =>
b=357-210=147 [input]solve( b+g=357, b/g=7/10 )[/input]
+3144 
