Number of boys=x
number of girls=y.
We can suggest this system of equations:
x/y=8/7 ⇒x=8y/7
x+y=195
this system of equations can be solve by substitution method.
(8y/7)+y=195
least common multiple=7
8y+7y=1365
15y=1365
y=1365/15
y=91
x=8y/7
x=8*91 / 7
x=728/7
x=104
Answer: there were 104 boy campers and 91 girl campers.